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Tuesday, May 22, 2007
The Trapiche Growth Phenomenon
There are various interpretations on the trapiche growth phenomena in colored stones. In the past experts got confused with the unusual growth pattern to twinning. The unusual growth pattern is usually visible in beryl, variety emerald, (Muzo, La Pena, Coscuez) and corundum, variety ruby and sapphire (Burma(Mong Hsu) and Vietnam). One theory is that the phenomenon in beryl and corundum are due to skeletal or dendritic growth, where edges and corners tend to grow much faster than the faces of a crystal. Another interpretation on the phenomenon in trapiche rubies and sapphires from Burma and Vietnam are due to skeletal growth followed by layer-by-layer growth. To make a long story short, rapid growth and changes in the growth conditions are believed to be the origin of the unusual patterns in beryl and corundum. The trapiche phenomenon is also seen in andalusite, tourmaline, and quartz. For now there are no nomenclatures for fixed star patterns that are being offered as trapiche in the gem market.
A Question Of Origin: A Different View
(via Gemological Digest, Vol.3, No.1, 1990) Charles A Schiffman writes:
Relating a source to the presence of certain inclusions or other physical properties is not a recent idea, but goes back to the last century. A good example in the literature is found in Max Bauer’s Edelsteinkunde, 3rd edition, Tauchnitz Verlag, 1896/1932; the author points out the great importance of inclusions in determining origins (page 499) and goes on about their description.
In more recent times, in the Handbook Of Gem Identification by R.T.Liddicoat, 11th edition, GIA, 1981, typical inclusions related to sources are quoted (pages 88-89, 95-96).
Inclusions As A Means Of Gemstone Identification by E.Gubelin, GIA, 1953, has been the standard course book at the GIA on the matter of inclusions related to source.
That gemstones of certain sources were highly favored long ago is a historical fact, independent from gemology.
This writer recalls one merchant who was proud because he dealt only in Burma rubies that he bought directly from Burma, following requests from customers in the jewelry trade, and he was not an isolated case.
The trade has a strong demand for origins that is documented by the Definitions of the CIBJO (published about 1968) in Europe, a body grouping a majority of dealers and retailers. The following is extracted from CIBJO:
Art.2: Designation of color and place of origin (a) names of gem localities used heretofore to describe the color of gemstones, cannot be used any longer (b) indications of place of origin can be only added if the origin is known and can actually be corroborated. This proof may be given either by physical properties, or by the stone’s inclusions, in so far as they are characteristic of a definite area.
Obviously there are limitations to finding out origins, i.e the absence of characteristic features. For this reason, the origin of many specimens of such gemstones as garnet, tourmaline and quart cannot be found.
An interesting point is that considering these limitations, where no origin may be objectively ascertained, a lab sometimes faces little understanding in trade circles.
Answering the demand from the market for general testing and for determination of origin, Gubelin Laboratory extended its activities (previously only for the company’s own needs) to outside inquiries in the late 1960’s.
Time has not stood still since then. Investigation has become a challenge to go beyond routine methods, using more complex instrumentation. Even so, some limitations will remain in the feasibility of this complex and difficult task, in an effort to base it on objective methods.
On the other side, the gemologist familiar with this field is conscious of the big commercial assets involved by people chasing the rare and exceptional items. This attitude is a very human one, so that it is hard to believe that interested parties will just forget about demanding origin information.
Showing different aspect of the question in this magazine will hopefully lead to a better understanding of the parties concerned, to improve their cooperation and contribute to solving pending questions.
Relating a source to the presence of certain inclusions or other physical properties is not a recent idea, but goes back to the last century. A good example in the literature is found in Max Bauer’s Edelsteinkunde, 3rd edition, Tauchnitz Verlag, 1896/1932; the author points out the great importance of inclusions in determining origins (page 499) and goes on about their description.
In more recent times, in the Handbook Of Gem Identification by R.T.Liddicoat, 11th edition, GIA, 1981, typical inclusions related to sources are quoted (pages 88-89, 95-96).
Inclusions As A Means Of Gemstone Identification by E.Gubelin, GIA, 1953, has been the standard course book at the GIA on the matter of inclusions related to source.
That gemstones of certain sources were highly favored long ago is a historical fact, independent from gemology.
This writer recalls one merchant who was proud because he dealt only in Burma rubies that he bought directly from Burma, following requests from customers in the jewelry trade, and he was not an isolated case.
The trade has a strong demand for origins that is documented by the Definitions of the CIBJO (published about 1968) in Europe, a body grouping a majority of dealers and retailers. The following is extracted from CIBJO:
Art.2: Designation of color and place of origin (a) names of gem localities used heretofore to describe the color of gemstones, cannot be used any longer (b) indications of place of origin can be only added if the origin is known and can actually be corroborated. This proof may be given either by physical properties, or by the stone’s inclusions, in so far as they are characteristic of a definite area.
Obviously there are limitations to finding out origins, i.e the absence of characteristic features. For this reason, the origin of many specimens of such gemstones as garnet, tourmaline and quart cannot be found.
An interesting point is that considering these limitations, where no origin may be objectively ascertained, a lab sometimes faces little understanding in trade circles.
Answering the demand from the market for general testing and for determination of origin, Gubelin Laboratory extended its activities (previously only for the company’s own needs) to outside inquiries in the late 1960’s.
Time has not stood still since then. Investigation has become a challenge to go beyond routine methods, using more complex instrumentation. Even so, some limitations will remain in the feasibility of this complex and difficult task, in an effort to base it on objective methods.
On the other side, the gemologist familiar with this field is conscious of the big commercial assets involved by people chasing the rare and exceptional items. This attitude is a very human one, so that it is hard to believe that interested parties will just forget about demanding origin information.
Showing different aspect of the question in this magazine will hopefully lead to a better understanding of the parties concerned, to improve their cooperation and contribute to solving pending questions.
When And Where Color Names Developed
Here is an interesting overview on the origin of color for the colored stone dealers, jewelers, gemologists and consumers.
Methuen writes:
Near the medieval village of Santillana del Mar in Northern Spain are the caves of Altamira, which contain some of the world’s most famous pre-historic paintings. In the flickering yellow light of a torch, cavemen saw bison, wild pigs, deer and horses painted on the cave walls in strong red earth, black and yellow ochre. The Cromagnon artist who painted these animals some 20000 years ago captured their movement with astonishing realism. In Lascaux and many other pre-historic caves, paintings of animals, rendered in similar colors and with equal artistry, have also been discovered.
The use of colors, however, extends even farther back in time, perhaps as much as 150,000 to 200,000 years. Ice age man buried his dead in red ochre or painted their bones a red color, he had observed that the flow of red blood meant the difference between life and death and probably believed that the color red itself was therefore life-giving.
The ability of Ice Age man to distinguish colors as existing independently of objects meant that the art of color abstraction had already been born. With its development arose the need for color names to identify these new concepts. To begin with, colors were probably given the same names as the paints, obtained from blood or ochre, which were used to produce them. In the oldest Indo-European language, Sanskrit, rudhira means blood; the first part of this word appears again in the Greek and Latin words for red (erythros and rutilus), as well as in the word red in many modern languages, such as the German rot, the Danish rod. Even the Eskimo word for red, aupaluktak, is derived from the word for blood, auk.
Man was probably long aware of the beauty inherent in the colors of his natural surroundings—the blue of the sky, the radiant orange and red hues of a sunset, the variety of colors found in flowers. But he probably was not aware of color as an independent concept until the idea of color assumed tangible form in its use for decorative or religious purposes. Since the concept of color as an independent entity is assumed to precede color names, the availability of materials which could be used as pigments was a prerequisite for the development of such names. A study of many cultures through the ages reveals that the use of an increasing variety of colors is accompanied by the development of words to characterize them.
The cave paintings described were rendered in only five colors: yellow, orange, red, brown and black. It is not until about 4500 B.C that we first find evidence of the use of blue (in the so-called Halaf culture in Mesopotamia). In Egypt, malachite green was used as a pigment in cosmetics before the era of the dynasties. In the Egypt and Babylonia of 4000 B.C we find an increasing number of colors used in ceramics, architecture, paintings and sculpture. Around 3000-2500 B.C, the Sumarians established a culture in Babylonia that evidenced a wealth of colors. There, the splendid blue stone, lapis lazuli, as well as other minerals and precious stones, were used for ornamental purpose. The Phoenicians discovered the color purple, which they made from a kind of whelk, and used to dye their clothes. The Egyptians introduced the use of blue purple and violet.
The knowledge and use of color traveled across Crete to Greece around 1600-1400 B.C. The use of contrasting combinations, such as yellow and light blue or red and blue, appears in the Golden Age of Greek culture between 600-400 B.C. The art of mixing colors to form new variations had long since been learned and the literature of the time offers a considerable selection of color names. When adopted by the Romans, these names formed the basis of the development of color names in most European languages.
Methuen writes:
Near the medieval village of Santillana del Mar in Northern Spain are the caves of Altamira, which contain some of the world’s most famous pre-historic paintings. In the flickering yellow light of a torch, cavemen saw bison, wild pigs, deer and horses painted on the cave walls in strong red earth, black and yellow ochre. The Cromagnon artist who painted these animals some 20000 years ago captured their movement with astonishing realism. In Lascaux and many other pre-historic caves, paintings of animals, rendered in similar colors and with equal artistry, have also been discovered.
The use of colors, however, extends even farther back in time, perhaps as much as 150,000 to 200,000 years. Ice age man buried his dead in red ochre or painted their bones a red color, he had observed that the flow of red blood meant the difference between life and death and probably believed that the color red itself was therefore life-giving.
The ability of Ice Age man to distinguish colors as existing independently of objects meant that the art of color abstraction had already been born. With its development arose the need for color names to identify these new concepts. To begin with, colors were probably given the same names as the paints, obtained from blood or ochre, which were used to produce them. In the oldest Indo-European language, Sanskrit, rudhira means blood; the first part of this word appears again in the Greek and Latin words for red (erythros and rutilus), as well as in the word red in many modern languages, such as the German rot, the Danish rod. Even the Eskimo word for red, aupaluktak, is derived from the word for blood, auk.
Man was probably long aware of the beauty inherent in the colors of his natural surroundings—the blue of the sky, the radiant orange and red hues of a sunset, the variety of colors found in flowers. But he probably was not aware of color as an independent concept until the idea of color assumed tangible form in its use for decorative or religious purposes. Since the concept of color as an independent entity is assumed to precede color names, the availability of materials which could be used as pigments was a prerequisite for the development of such names. A study of many cultures through the ages reveals that the use of an increasing variety of colors is accompanied by the development of words to characterize them.
The cave paintings described were rendered in only five colors: yellow, orange, red, brown and black. It is not until about 4500 B.C that we first find evidence of the use of blue (in the so-called Halaf culture in Mesopotamia). In Egypt, malachite green was used as a pigment in cosmetics before the era of the dynasties. In the Egypt and Babylonia of 4000 B.C we find an increasing number of colors used in ceramics, architecture, paintings and sculpture. Around 3000-2500 B.C, the Sumarians established a culture in Babylonia that evidenced a wealth of colors. There, the splendid blue stone, lapis lazuli, as well as other minerals and precious stones, were used for ornamental purpose. The Phoenicians discovered the color purple, which they made from a kind of whelk, and used to dye their clothes. The Egyptians introduced the use of blue purple and violet.
The knowledge and use of color traveled across Crete to Greece around 1600-1400 B.C. The use of contrasting combinations, such as yellow and light blue or red and blue, appears in the Golden Age of Greek culture between 600-400 B.C. The art of mixing colors to form new variations had long since been learned and the literature of the time offers a considerable selection of color names. When adopted by the Romans, these names formed the basis of the development of color names in most European languages.
Monday, May 21, 2007
Gem Mining And Sustainable Environmental Management in Sri Lanka
2007: How many dealers, jewelers and consumers actually know where the stones come from? Very few. Only a lucky few have had the opportunity to actually see the working of a mine. The island of Sri Lanka is blessed with virtually all known colored stones in the world, but most dealers, jewelers and consumers focus on high value stones and that's all they know. But the truth is otherwise; Sri Lanka is also a treasure trove for rare stones and the author explains in detail the mining methodology that is good for Sri Lanka with minimum environmental damage.
(via Journal of Gemmology, Vol.28, No.3, July 2002) P.G.R Dharmaratne writes:
Abstract
Various methods of accessing alluvial gem gravels (known as illama) in Sri Lanka for the extraction of gemstones, such as open pits, shafts and tunnels, and dredging, are briefly summarized. The methods adopted to minimize environmental damage caused by mining include: introduction of legislation, restriction on types of mining methods permitted, awareness programmes and restoration of mined-out lands. The lessons learned by the Sri Lankan gem industry, with centuries of experience, can be applied to other gem producing countries.
Introduction
Mining of minerals for the consumption by human beings started many centuries ago and if it were not for minerals and their products, the world would be without many of the material comforts for its population today. For example, life can not be imagined without having metal for machinery and motor vehicles, cement for construction, fuel and minerals for energy production, all of which are products of mining. Gems, though not an essential commodity, on the other hand make life more beautiful and attractive. So it can be said that minerals bring comforts for the body while gems give comfort for the senses and the eye in particular. Since minerals play such an important role in the lives of people, it is the duty of all of us to extract them with least possible damage to the environment in which we live.
Gem mining
Introduction
Sri Lanka has been identified as one of the earliest sources of gems in the world, and is still a leading producer. Mining activities were not properly organized until early 1970s; before 1970, gem mining was done haphazardly and different regulations were in force in different districts. With the establishment of the State Gem Corporation, predecessor to the National Gem and Jewellery Authority, in 1972 all the activities were brought under one institution and many regional offices were established to issue licenses for mining and thereby supervise and minimize the impact on the environment. One of the main objectives of the State Gem Corporation was the development, regulation and control of the gem industry. Mining increased rapidly with provision of many facilities to gem exporters. While legalized mining reduced the damage to the environment, illicit mining also continued and unlike licensed mining, this caused more extensive damage to the environment.
Mining by means of open pits
A gem bearing gravel bed occurring on or near the surface is exploited using mammoties and crowbars to excavate open pits most of which are without any support on their side walls. The miner fills bamboo baskets with grave, and throws them upward to the waiting hands of another man at the pit head. The method used for bailing out water from the pit depends on the rate of water seepage. It can be done by hand with buckets or by using mechanized water pumps. When the gem bearing gravel is reached, it is collected separately at the pit head, and washed in running water in closely woven conical bamboo baskets. If there is a shortage of water, material from surface digging can be dry sieved after removing the larger rocks by hand. Only the remaining material needs to be washed to remove dust and clay. With the correct techniques of washing, gemstones can be concentrated at the bottom of the sieve.
The use of bulldozers and scrapers has been allowed in special circumstances such as where very thin gem gravel beds occur, or in areas which have been mined out by open pits or shafts and tunnels. This machinery is used to remove the overburden, since open pit mining is no longer economical in such situations.
Mining by shafts and tunnels
The placer deposits of gems (illama) and in situ deposits occurring below a certain depth are mined by sinking shafts and excavating tunnels. In Sri Lanka, only placer deposits are mined by sinking pits, but for deeper deposits, recovery of the illama by successively deeper pits becomes uneconomical. In such situations, it is common practice to excavate horizontal tunnels at the level of the gem bearing gravel layer in order to recover gemstones. In small operations through hard ground, the shafts are either round (2m diameter) or square (2m sides), but in soft ground (e.g beneath paddy fields), they are rectangular in section, measuring about 2 x 4m.
The shaft is reinforced with timber crossbeams (from rubber trees0 while fern foliage is pushed between the sides of the shaft and vertical struts (arecanut trunks) are driven behind the crossbeams, to prevent the damp sidewalls from caving in. While shafts are 3-4m deep, clay and sand shoveled into small bamboo baskets are manually lifted up to the shaft head. Deeper shafts utilize manually operated winches to lift excavated material and water. As the rate of water flow increases, traditional methods of removing water are replaced by water pumps.
The illama is collected separately near the shaft at a place where the ground is specially leveled. The illama can be up to a few meters thick, and generally rests directly on decomposed rock (malawa) or unweathered rock (parugala). Washing the illama is done in a nearby stream or in a pond specially constructed for the purpose. The miners stand waist deep in the pond and move the baskets in a circular motion to remove all the lighter materials. Washing is continued for about half an hour with more illama being intermittently fed into the baskets. During the washing, lighter material collects at the top of the basket and is hand sorted and thrown out of the pond, while the heavy gem bearing material settles at the bottom of the basket. After washing, the baskets are stacked. Later, an experienced miner collects the gems while sweeping the gravel back and forth by hand.
When illama is at a fairly deep level (>8m) horizontal tunnels, 1-2m high, are excavated from the bottom of the shaft so that the floor of the tunnel follows or lies on the rock layer underlying the illama. As the tunnels are excavated deeper into the surrounding area, an adequate supply of fresh air and oxygen for breathing as well as for lighting candles, becomes more difficult. In such situations, air pumps are installed to provide fresh air into the mine. The tunnels are supported with timber and crossbeams similar to those of the main shaft. In Sri Lanka, over 60 percent of the mining is done by shafts and tunnels.
River dredging
When the gem bearing placer deposits occur at the bottom of a shallow river, long-handled mammoties (a type of manual scraper with the blade perpendicular to the handle so that material can be scooped up towards the user) are used to scoop up the gravel. To prepare for this process, a brushwood dam is erected at a place where the river slows down naturally, and the water is allowed to escape from one side of the dam. Using long-handled mammoties, the overlying sand and gravel are scooped over the place where water passes through. This procedure is continued until the illama is reached. The illama is then loosened by using long pointed steel rods and is also scooped into the moving water which removes the lighter and finer minerals, leaving heavy gem minerals behind. Good gemstones can be easily seen and hand picked and the rest of the gravel is washed in the same manner as discussed earlier.
In the past, gravel pumps and dredgers could be used to extract the overburden and gem gravel, but they are banned at present because of the damage they cause to river banks.
Environmental management
Causes of environmental damage
Damage to the environment due to gem mining has been discussed by de Silva (1989), Rupasinghe and Cooray (1993) and Dharmaratne (1994).
1. Damage to land and vegetation cover
Most damage to land caused by mining activities is due to open-pit methods. In particular, mining for topaz involves large volumes of earth to recover gemstones. Illicit miners leave behind larger craters and pits, particularly in the forests, which fill with water and become breeding grounds for mosquitoes; this in turn endangers the lives of people and animals.
Tree trunks are used to support the walls and roofs of shafts and tunnels and the flow of earth into the workings is prevented by lagging with variety of fern (kekilla). This fern has strong roots which bind the soil and prevent soil erosion. Large areas of fern cover are harvested annually to support many thousands of gem pits, and consequently, during the monsoon rains heavy erosion occurs in these areas.
2. Damage to plantations
When near-surface gem deposits are discovered in plantations of tea, rubber, coconut or pepper, mining is carried out without any consideration or respect for the trees. Valuable trees are either removed deliberately or fall down due to excavation. The loss of good plantations, damages the national economy.
3. Damage to rivers and river banks
Gem mining in rivers and streams is allowed by the NGJA only because of the uncontrollable nature of illicit mining. Illicit miners not only dredge the river bottom but also damage river banks by undercutting. Their operations may take place by day and by night. During dredging, fine clay particles can be released into suspension in the water and cause the death of river species; they can also prevent use of water for bathing and drinking. Furthermore, the sedimentation of waterways and dams reduces the efficiency of hydroelectric power plants.
4. Damage to buildings and properties
Tunneling under roads, buildings, canals, culverts and other structures can cause untold damage. There are many instances of land owners literally undermining their own properties, because it is sometimes worth the risk of forgoing a property in the hope of recovering high value gemstones.
Legislature
The State Gem Corporation Act No.13 of 1971 was repealed in 1993 and the National Gem and Jewellery Authority Act No.50 of 1993 came into effect with regard to the gem and jewellery industry. The Act states that:
‘No person shall carry on the gem industry except under the authority of a license issued by the Authority and every person who commits an offence under this Act shall on conviction after a trial before a magistrate, be liable to a fine not exceeding one million rupees or to imprisonment for a period not exceeding five years or to both such fine and imprisonment.’
The NGJA can, with the consent of the relevant parties, having regard to the circumstances in which any offence under this act was committed, compound such offence for a sum of not exceeding one third the maximum fine imposable.
The regulations in respect of the gem and jewelry industry were gazetted in 1972. Accordingly a license for mining for gems is issued under the following conditions:
1. The land owner/co-owners should give consent in writing to the prospective license.
2. If the land in question is cultivated; the consent of the cultivator too should be obtained if he is not the owner of the land.
3. In the case of cultivated land the consent of the regional office of the Agrarian Services Department should be obtained and the ASD takes a security deposit for each pit to ensure that the license restores the land after mining. The NGJA also takes a security deposit for each pit to ensure that the pits are closed, as is the responsibility of the NGJA to restore lands after mining. In the case of river dredging, substantial security deposits are required by the NGJA for the possible work involved in much larger than that for restoration of mining damage on high ground.
4. In mining cultivated land and rivers, water pumps are the only machinery allowed. Backhoes are permitted only in special circumstances and only with a very large security deposit since the excavations created are much larger than in normal pit mining.
Control of illicit gem mining
Raids are conducted with the assistance of the police to enforce the regulations and to apprehend offenders, because sometimes illicit gem miners attack unarmed field officers. There have been occasions in the past when even armed police have been the victims of illicit gem miners who sometimes flock in their thousands to new gem deposits discovered near the surface. The police have the authority to conduct their own raids and on such occasions, offenders are brought before a court of justice and due punishments is given.
Illicit mining in State lands, rivers and roads, or their reservations, is treated very seriously and the punishments are high compared with those for illicit mining on private land. Roads, rivers and their reservations, which comprise about 10 meters one each side of the road or river, belong to the government, and construction or excavation is not allowed in the reservations in order to safeguard these routes. If, for example, a water pump is seized on private land, it may be released with a fine of Rs.2500, whereas if the same pump were seized in one of the above mentioned locations, the fine may be a third of the value of the pump if it is a first offence, two thirds of the value if the offence is repeated and on a third offence the pump is forfeited to the State. Water pumps are the most common machines used in gem mining, and although gravel pumps, bulldozers and scrapers are rarely used, they too can be seized if used illicitly. This practice has been in operation for many years. However it has now been found that it is not a sufficient deterrent and therefore action has been taken to increase the severity of the punishment and to seize the machinery on the first offence. This is done particularly to discourage the use of gravel pumps in rivers and bulldozers and scrapers in large scale excavations in illicit mines.
Restoration of mined out lands
The security deposits kept at the NGJA are released only if the pits are closed and the lands are restored in a fit state for cultivation. Most often, when the value of gemstones found is very high, miners ignore the need to close pits and reclaim the land. The NGJA has established a rehabilitation fund with the money from those unclaimed deposits. During the recent past this fund has financed the following activities:
1. Conducting seminars for the gem mining community to educate them in environmentally friendly mining methods and restoration of lands.
2. Restoration of river banks by erecting brushwood dams along the original river boundary and filling the excavated area behind it; also planting suitable trees along the river banks.
3. Restoration of mined-out land by using bulldozers and scrapers and planting trees.
Conclusions
Mining by any method and for any mineral cause environmental damage and the only action that can be taken is to ensure that the damage is minimized. In the case of gem mining in Sri Lanka, many hundreds of thousands of people are engaged in gem mining, with or without a license from the NGJA. While the damage to the environment by legalized mining is minimal, the greatest harm comes from illicit mining and results in unfilled pits, soil heaps and pollution of waterways.
Illicit gem mining is not a problem specific to Sri Lanka, but faced by all gem producing countries. The discoveries of near surface deposits have caused gem rushes involving thousands of people in Sri Lanka, Madagascar, Tanzania, Brazil and in many other countries. Licensed mining can be supervised and strict rules can be enforced to reduce the environmental degradation. The field officers of the NGJA with the assistance of police make every effort to stop illicit mining, but the nature of such operations and the number of people involved prevents its complete eradication. The damage that illicit mining causes is offset to some extent by a rehabilitation fund established by the NGJA which is used to restore mined out lands.
(via Journal of Gemmology, Vol.28, No.3, July 2002) P.G.R Dharmaratne writes:
Abstract
Various methods of accessing alluvial gem gravels (known as illama) in Sri Lanka for the extraction of gemstones, such as open pits, shafts and tunnels, and dredging, are briefly summarized. The methods adopted to minimize environmental damage caused by mining include: introduction of legislation, restriction on types of mining methods permitted, awareness programmes and restoration of mined-out lands. The lessons learned by the Sri Lankan gem industry, with centuries of experience, can be applied to other gem producing countries.
Introduction
Mining of minerals for the consumption by human beings started many centuries ago and if it were not for minerals and their products, the world would be without many of the material comforts for its population today. For example, life can not be imagined without having metal for machinery and motor vehicles, cement for construction, fuel and minerals for energy production, all of which are products of mining. Gems, though not an essential commodity, on the other hand make life more beautiful and attractive. So it can be said that minerals bring comforts for the body while gems give comfort for the senses and the eye in particular. Since minerals play such an important role in the lives of people, it is the duty of all of us to extract them with least possible damage to the environment in which we live.
Gem mining
Introduction
Sri Lanka has been identified as one of the earliest sources of gems in the world, and is still a leading producer. Mining activities were not properly organized until early 1970s; before 1970, gem mining was done haphazardly and different regulations were in force in different districts. With the establishment of the State Gem Corporation, predecessor to the National Gem and Jewellery Authority, in 1972 all the activities were brought under one institution and many regional offices were established to issue licenses for mining and thereby supervise and minimize the impact on the environment. One of the main objectives of the State Gem Corporation was the development, regulation and control of the gem industry. Mining increased rapidly with provision of many facilities to gem exporters. While legalized mining reduced the damage to the environment, illicit mining also continued and unlike licensed mining, this caused more extensive damage to the environment.
Mining by means of open pits
A gem bearing gravel bed occurring on or near the surface is exploited using mammoties and crowbars to excavate open pits most of which are without any support on their side walls. The miner fills bamboo baskets with grave, and throws them upward to the waiting hands of another man at the pit head. The method used for bailing out water from the pit depends on the rate of water seepage. It can be done by hand with buckets or by using mechanized water pumps. When the gem bearing gravel is reached, it is collected separately at the pit head, and washed in running water in closely woven conical bamboo baskets. If there is a shortage of water, material from surface digging can be dry sieved after removing the larger rocks by hand. Only the remaining material needs to be washed to remove dust and clay. With the correct techniques of washing, gemstones can be concentrated at the bottom of the sieve.
The use of bulldozers and scrapers has been allowed in special circumstances such as where very thin gem gravel beds occur, or in areas which have been mined out by open pits or shafts and tunnels. This machinery is used to remove the overburden, since open pit mining is no longer economical in such situations.
Mining by shafts and tunnels
The placer deposits of gems (illama) and in situ deposits occurring below a certain depth are mined by sinking shafts and excavating tunnels. In Sri Lanka, only placer deposits are mined by sinking pits, but for deeper deposits, recovery of the illama by successively deeper pits becomes uneconomical. In such situations, it is common practice to excavate horizontal tunnels at the level of the gem bearing gravel layer in order to recover gemstones. In small operations through hard ground, the shafts are either round (2m diameter) or square (2m sides), but in soft ground (e.g beneath paddy fields), they are rectangular in section, measuring about 2 x 4m.
The shaft is reinforced with timber crossbeams (from rubber trees0 while fern foliage is pushed between the sides of the shaft and vertical struts (arecanut trunks) are driven behind the crossbeams, to prevent the damp sidewalls from caving in. While shafts are 3-4m deep, clay and sand shoveled into small bamboo baskets are manually lifted up to the shaft head. Deeper shafts utilize manually operated winches to lift excavated material and water. As the rate of water flow increases, traditional methods of removing water are replaced by water pumps.
The illama is collected separately near the shaft at a place where the ground is specially leveled. The illama can be up to a few meters thick, and generally rests directly on decomposed rock (malawa) or unweathered rock (parugala). Washing the illama is done in a nearby stream or in a pond specially constructed for the purpose. The miners stand waist deep in the pond and move the baskets in a circular motion to remove all the lighter materials. Washing is continued for about half an hour with more illama being intermittently fed into the baskets. During the washing, lighter material collects at the top of the basket and is hand sorted and thrown out of the pond, while the heavy gem bearing material settles at the bottom of the basket. After washing, the baskets are stacked. Later, an experienced miner collects the gems while sweeping the gravel back and forth by hand.
When illama is at a fairly deep level (>8m) horizontal tunnels, 1-2m high, are excavated from the bottom of the shaft so that the floor of the tunnel follows or lies on the rock layer underlying the illama. As the tunnels are excavated deeper into the surrounding area, an adequate supply of fresh air and oxygen for breathing as well as for lighting candles, becomes more difficult. In such situations, air pumps are installed to provide fresh air into the mine. The tunnels are supported with timber and crossbeams similar to those of the main shaft. In Sri Lanka, over 60 percent of the mining is done by shafts and tunnels.
River dredging
When the gem bearing placer deposits occur at the bottom of a shallow river, long-handled mammoties (a type of manual scraper with the blade perpendicular to the handle so that material can be scooped up towards the user) are used to scoop up the gravel. To prepare for this process, a brushwood dam is erected at a place where the river slows down naturally, and the water is allowed to escape from one side of the dam. Using long-handled mammoties, the overlying sand and gravel are scooped over the place where water passes through. This procedure is continued until the illama is reached. The illama is then loosened by using long pointed steel rods and is also scooped into the moving water which removes the lighter and finer minerals, leaving heavy gem minerals behind. Good gemstones can be easily seen and hand picked and the rest of the gravel is washed in the same manner as discussed earlier.
In the past, gravel pumps and dredgers could be used to extract the overburden and gem gravel, but they are banned at present because of the damage they cause to river banks.
Environmental management
Causes of environmental damage
Damage to the environment due to gem mining has been discussed by de Silva (1989), Rupasinghe and Cooray (1993) and Dharmaratne (1994).
1. Damage to land and vegetation cover
Most damage to land caused by mining activities is due to open-pit methods. In particular, mining for topaz involves large volumes of earth to recover gemstones. Illicit miners leave behind larger craters and pits, particularly in the forests, which fill with water and become breeding grounds for mosquitoes; this in turn endangers the lives of people and animals.
Tree trunks are used to support the walls and roofs of shafts and tunnels and the flow of earth into the workings is prevented by lagging with variety of fern (kekilla). This fern has strong roots which bind the soil and prevent soil erosion. Large areas of fern cover are harvested annually to support many thousands of gem pits, and consequently, during the monsoon rains heavy erosion occurs in these areas.
2. Damage to plantations
When near-surface gem deposits are discovered in plantations of tea, rubber, coconut or pepper, mining is carried out without any consideration or respect for the trees. Valuable trees are either removed deliberately or fall down due to excavation. The loss of good plantations, damages the national economy.
3. Damage to rivers and river banks
Gem mining in rivers and streams is allowed by the NGJA only because of the uncontrollable nature of illicit mining. Illicit miners not only dredge the river bottom but also damage river banks by undercutting. Their operations may take place by day and by night. During dredging, fine clay particles can be released into suspension in the water and cause the death of river species; they can also prevent use of water for bathing and drinking. Furthermore, the sedimentation of waterways and dams reduces the efficiency of hydroelectric power plants.
4. Damage to buildings and properties
Tunneling under roads, buildings, canals, culverts and other structures can cause untold damage. There are many instances of land owners literally undermining their own properties, because it is sometimes worth the risk of forgoing a property in the hope of recovering high value gemstones.
Legislature
The State Gem Corporation Act No.13 of 1971 was repealed in 1993 and the National Gem and Jewellery Authority Act No.50 of 1993 came into effect with regard to the gem and jewellery industry. The Act states that:
‘No person shall carry on the gem industry except under the authority of a license issued by the Authority and every person who commits an offence under this Act shall on conviction after a trial before a magistrate, be liable to a fine not exceeding one million rupees or to imprisonment for a period not exceeding five years or to both such fine and imprisonment.’
The NGJA can, with the consent of the relevant parties, having regard to the circumstances in which any offence under this act was committed, compound such offence for a sum of not exceeding one third the maximum fine imposable.
The regulations in respect of the gem and jewelry industry were gazetted in 1972. Accordingly a license for mining for gems is issued under the following conditions:
1. The land owner/co-owners should give consent in writing to the prospective license.
2. If the land in question is cultivated; the consent of the cultivator too should be obtained if he is not the owner of the land.
3. In the case of cultivated land the consent of the regional office of the Agrarian Services Department should be obtained and the ASD takes a security deposit for each pit to ensure that the license restores the land after mining. The NGJA also takes a security deposit for each pit to ensure that the pits are closed, as is the responsibility of the NGJA to restore lands after mining. In the case of river dredging, substantial security deposits are required by the NGJA for the possible work involved in much larger than that for restoration of mining damage on high ground.
4. In mining cultivated land and rivers, water pumps are the only machinery allowed. Backhoes are permitted only in special circumstances and only with a very large security deposit since the excavations created are much larger than in normal pit mining.
Control of illicit gem mining
Raids are conducted with the assistance of the police to enforce the regulations and to apprehend offenders, because sometimes illicit gem miners attack unarmed field officers. There have been occasions in the past when even armed police have been the victims of illicit gem miners who sometimes flock in their thousands to new gem deposits discovered near the surface. The police have the authority to conduct their own raids and on such occasions, offenders are brought before a court of justice and due punishments is given.
Illicit mining in State lands, rivers and roads, or their reservations, is treated very seriously and the punishments are high compared with those for illicit mining on private land. Roads, rivers and their reservations, which comprise about 10 meters one each side of the road or river, belong to the government, and construction or excavation is not allowed in the reservations in order to safeguard these routes. If, for example, a water pump is seized on private land, it may be released with a fine of Rs.2500, whereas if the same pump were seized in one of the above mentioned locations, the fine may be a third of the value of the pump if it is a first offence, two thirds of the value if the offence is repeated and on a third offence the pump is forfeited to the State. Water pumps are the most common machines used in gem mining, and although gravel pumps, bulldozers and scrapers are rarely used, they too can be seized if used illicitly. This practice has been in operation for many years. However it has now been found that it is not a sufficient deterrent and therefore action has been taken to increase the severity of the punishment and to seize the machinery on the first offence. This is done particularly to discourage the use of gravel pumps in rivers and bulldozers and scrapers in large scale excavations in illicit mines.
Restoration of mined out lands
The security deposits kept at the NGJA are released only if the pits are closed and the lands are restored in a fit state for cultivation. Most often, when the value of gemstones found is very high, miners ignore the need to close pits and reclaim the land. The NGJA has established a rehabilitation fund with the money from those unclaimed deposits. During the recent past this fund has financed the following activities:
1. Conducting seminars for the gem mining community to educate them in environmentally friendly mining methods and restoration of lands.
2. Restoration of river banks by erecting brushwood dams along the original river boundary and filling the excavated area behind it; also planting suitable trees along the river banks.
3. Restoration of mined-out land by using bulldozers and scrapers and planting trees.
Conclusions
Mining by any method and for any mineral cause environmental damage and the only action that can be taken is to ensure that the damage is minimized. In the case of gem mining in Sri Lanka, many hundreds of thousands of people are engaged in gem mining, with or without a license from the NGJA. While the damage to the environment by legalized mining is minimal, the greatest harm comes from illicit mining and results in unfilled pits, soil heaps and pollution of waterways.
Illicit gem mining is not a problem specific to Sri Lanka, but faced by all gem producing countries. The discoveries of near surface deposits have caused gem rushes involving thousands of people in Sri Lanka, Madagascar, Tanzania, Brazil and in many other countries. Licensed mining can be supervised and strict rules can be enforced to reduce the environmental degradation. The field officers of the NGJA with the assistance of police make every effort to stop illicit mining, but the nature of such operations and the number of people involved prevents its complete eradication. The damage that illicit mining causes is offset to some extent by a rehabilitation fund established by the NGJA which is used to restore mined out lands.
A Question Of Origin: A Different View
2007: Here is an interesting perspective on the question of origin from the father of inclusion studies.
(via Gemological Digest, Vol.3, No.1, 1990) Dr Eduard Gubelin writes:
The pros and cons of origin reports have been discussed on so many occasions during numerous conferences that I do not wish to repeat the arguments. Yet my strongest arguments in favor of origin reports are:
a) The fact that gemstones are very valuable and rare objects, and as such are entitled to be compared with objects of art and antiquity. It is customary that art and antique collectors request and receive a certificate of origin and authenticity. I see no reason why buyers of gemstones should not have the same right to ask for and obtain a certificate of origin and genuineness. The request for a certificate of origin need not necessarily be limited to the few precious gemstones (alexandrite, emerald, diamond, black opal, ruby and sapphire) but could be extended to the less expensive gemstones (beryls, chrysoberyls, peridot, quartz, topaz, tourmaline, spinel, etc). I have the feeling that my quite representative and comprehensive gem collection has been admired by all those prominent gemologists who have seen it because each individual specimen is marked with its origin. Why shouldn’t other buyers and collectors of gemstones be entitled to know the origin of their collector’s items? You know just as well I do that gemstones are among the items least commonly collected. Definitely much less than paintings, antiques, weapons, stamps or even such odd objects as hats, scarves and uniform buttons. Personally I am convinced that origin reports honestly and correctly stated would help a great deal to stimulate many more people to collect gemstones.
(b) My next argument in favor of origin reports is scientific: Of what value are the more recent and very profound investigations of, and publications on, original gem deposits such as those by Dr Hanni (about the emerald mines at Santa Terezinha da Goias, the emerald mine of Belmont near Itabira or the emerald deposit of Ankadilalana on Madagascar), or Dr Peter Keller’s research (on rubies from Mogok and those from Thailand), or my studies (of gem deposits of Sri Lanka, at Mogok, the jade occurrences in Northern Burma, and the gem deposits in Pakistan, and so son and so forth), if afterwards neither the authors of these studies nor other learned gemologists are allowed to profit from their intrinsic knowledge and experience? After all, the details in these very valuable articles about old and new gem deposits serve the purpose that gemstones occurring in the described deposits may be recognized as such by their particularities of origin. Thanks to Dr Hanni’ publications about emeralds from Santa Terezinha and those from Belmont, numerous interested gemologists are definitely capable of recognizing and distinguishing the emeralds from these two sources at first sight without any difficulty, and even discerning them from those originating, for instance, from Chivor or the Muzo area. Without bragging, I may emphasize that the staff of the Gubelin Laboratory under the directorship of Mr C A Schiffmann, as well myself, could very easily undertake such a distinction under the condition that the gemological properties agree with one or other of these well-known emerald deposits.
Your argument concerning the uranium pyrochlore inclusions in Pailin sapphires which have also been observed in Australian sapphires may seem to be correct, but it is not quite so, because in any scientific work, progress and new observations are made. Yet whenever a publication is made, the author can only state his knowledge at the time of writing. It is not his mistake if later on new discoveries are made, but he must be ready to correct his previously made incomplete or incorrect statement. Mr John Koivula did so in the Photoatlas of Inclusions In Gemstones. As a matter of fact, the text had already been typed when I learned that pyrochlore is also present in Australian sapphires. Consequently I not only corrected this statement, but presented further detailed knowledge by stating that urnanium pyrochlore is a frequent guest mineral in sapphires originating from a basaltic environment. Perhaps these arguments may enrich the discussion about this problem of origin reports.
(via Gemological Digest, Vol.3, No.1, 1990) Dr Eduard Gubelin writes:
The pros and cons of origin reports have been discussed on so many occasions during numerous conferences that I do not wish to repeat the arguments. Yet my strongest arguments in favor of origin reports are:
a) The fact that gemstones are very valuable and rare objects, and as such are entitled to be compared with objects of art and antiquity. It is customary that art and antique collectors request and receive a certificate of origin and authenticity. I see no reason why buyers of gemstones should not have the same right to ask for and obtain a certificate of origin and genuineness. The request for a certificate of origin need not necessarily be limited to the few precious gemstones (alexandrite, emerald, diamond, black opal, ruby and sapphire) but could be extended to the less expensive gemstones (beryls, chrysoberyls, peridot, quartz, topaz, tourmaline, spinel, etc). I have the feeling that my quite representative and comprehensive gem collection has been admired by all those prominent gemologists who have seen it because each individual specimen is marked with its origin. Why shouldn’t other buyers and collectors of gemstones be entitled to know the origin of their collector’s items? You know just as well I do that gemstones are among the items least commonly collected. Definitely much less than paintings, antiques, weapons, stamps or even such odd objects as hats, scarves and uniform buttons. Personally I am convinced that origin reports honestly and correctly stated would help a great deal to stimulate many more people to collect gemstones.
(b) My next argument in favor of origin reports is scientific: Of what value are the more recent and very profound investigations of, and publications on, original gem deposits such as those by Dr Hanni (about the emerald mines at Santa Terezinha da Goias, the emerald mine of Belmont near Itabira or the emerald deposit of Ankadilalana on Madagascar), or Dr Peter Keller’s research (on rubies from Mogok and those from Thailand), or my studies (of gem deposits of Sri Lanka, at Mogok, the jade occurrences in Northern Burma, and the gem deposits in Pakistan, and so son and so forth), if afterwards neither the authors of these studies nor other learned gemologists are allowed to profit from their intrinsic knowledge and experience? After all, the details in these very valuable articles about old and new gem deposits serve the purpose that gemstones occurring in the described deposits may be recognized as such by their particularities of origin. Thanks to Dr Hanni’ publications about emeralds from Santa Terezinha and those from Belmont, numerous interested gemologists are definitely capable of recognizing and distinguishing the emeralds from these two sources at first sight without any difficulty, and even discerning them from those originating, for instance, from Chivor or the Muzo area. Without bragging, I may emphasize that the staff of the Gubelin Laboratory under the directorship of Mr C A Schiffmann, as well myself, could very easily undertake such a distinction under the condition that the gemological properties agree with one or other of these well-known emerald deposits.
Your argument concerning the uranium pyrochlore inclusions in Pailin sapphires which have also been observed in Australian sapphires may seem to be correct, but it is not quite so, because in any scientific work, progress and new observations are made. Yet whenever a publication is made, the author can only state his knowledge at the time of writing. It is not his mistake if later on new discoveries are made, but he must be ready to correct his previously made incomplete or incorrect statement. Mr John Koivula did so in the Photoatlas of Inclusions In Gemstones. As a matter of fact, the text had already been typed when I learned that pyrochlore is also present in Australian sapphires. Consequently I not only corrected this statement, but presented further detailed knowledge by stating that urnanium pyrochlore is a frequent guest mineral in sapphires originating from a basaltic environment. Perhaps these arguments may enrich the discussion about this problem of origin reports.
Sunday, May 20, 2007
3 Lessons B-schools Miss Teaching
I wish the gemological schools taught the concepts as part of the program. Most gemologists who graduate lack soft skills and are unemployable for variety of reasons. Here is a thought-provoking article for self-examination.
Nalin Garg writes:
Business schools are great! They add value to students' education by actively providing insights into the learnings and practices of some of the world's best theorists, academicians and business leaders. B-schools certainly do teach you a lot, but then there is more that needs to be learnt.
Initiative and risk-taking: Learning from others' experiences is wise. The successes and failures of individuals and companies have shaped current-day management courses.
Each of those instances was pioneering in its time. There were a small percentage of risk-takers who lived to tell the tale, instantly defining newer paradigms. Each perspective comes with its assumptions and constraints, and it is up to the individual to challenge and break new ground.
Adaptability: To roll with the punches and come on top each time, an individual has to assimilate the operating environment and conditions and, using that as a base, act!
That is easier said than done since the environment itself changes so rapidly - be it politics, the economy, and competition or consumer preference. A motley combination of various, seemingly unrelated, factors interact to create this environment.
Each instance of variation has a counterbalancing impact on some other factor, with a resulting change in the operating environment. The skill to succeed in this ever-changing, always evolving environment resides in the person, not in the B-school he or she went to.
Application: B-school courses use models, metrics and terminology to get potential entrants into corporate roles off to a flying start. They speak of and relate to events in the same way, using the same jargon.
However, the correct application of a model or tool is usually an individual's discretion; it is his or her interpretation of the situation that forces a judgment, accurate or otherwise. The application of learning is the proof of the pudding - a realization of the latent knowledge in an actual business context, which rests squarely on the individual's shoulders.
B-schools, too, work continuously trying to bring in the best inputs possible, in terms of trends, preferences and principles, though the introduction of such knowledge in course curriculum happens only after it has been published or, at least, documented.
This involves significant lag time, and given the breadth and speed of change, this is an uphill and never-ending task.
In sum, a B-school is the basic foundation that equips individuals to get a firm footing in the corporate arena, but there are several other skills that one needs to assimilate to survive and succeed there.
But most important of all - don't forget to live and have fun. It is too easy to get caught up in the rat race; stay out of it. Spend the first few years of your corporate life with your nose down, bury your ego, enjoy every moment of your work and make sure that you do the best you can. Success will follow.
Nalin Garg graduated from Tata Institute of Social Sciences, Mumbai, in 1992
More info @ http://www.rediff.com/money/2007/may/16bschool.htm
Nalin Garg writes:
Business schools are great! They add value to students' education by actively providing insights into the learnings and practices of some of the world's best theorists, academicians and business leaders. B-schools certainly do teach you a lot, but then there is more that needs to be learnt.
Initiative and risk-taking: Learning from others' experiences is wise. The successes and failures of individuals and companies have shaped current-day management courses.
Each of those instances was pioneering in its time. There were a small percentage of risk-takers who lived to tell the tale, instantly defining newer paradigms. Each perspective comes with its assumptions and constraints, and it is up to the individual to challenge and break new ground.
Adaptability: To roll with the punches and come on top each time, an individual has to assimilate the operating environment and conditions and, using that as a base, act!
That is easier said than done since the environment itself changes so rapidly - be it politics, the economy, and competition or consumer preference. A motley combination of various, seemingly unrelated, factors interact to create this environment.
Each instance of variation has a counterbalancing impact on some other factor, with a resulting change in the operating environment. The skill to succeed in this ever-changing, always evolving environment resides in the person, not in the B-school he or she went to.
Application: B-school courses use models, metrics and terminology to get potential entrants into corporate roles off to a flying start. They speak of and relate to events in the same way, using the same jargon.
However, the correct application of a model or tool is usually an individual's discretion; it is his or her interpretation of the situation that forces a judgment, accurate or otherwise. The application of learning is the proof of the pudding - a realization of the latent knowledge in an actual business context, which rests squarely on the individual's shoulders.
B-schools, too, work continuously trying to bring in the best inputs possible, in terms of trends, preferences and principles, though the introduction of such knowledge in course curriculum happens only after it has been published or, at least, documented.
This involves significant lag time, and given the breadth and speed of change, this is an uphill and never-ending task.
In sum, a B-school is the basic foundation that equips individuals to get a firm footing in the corporate arena, but there are several other skills that one needs to assimilate to survive and succeed there.
But most important of all - don't forget to live and have fun. It is too easy to get caught up in the rat race; stay out of it. Spend the first few years of your corporate life with your nose down, bury your ego, enjoy every moment of your work and make sure that you do the best you can. Success will follow.
Nalin Garg graduated from Tata Institute of Social Sciences, Mumbai, in 1992
More info @ http://www.rediff.com/money/2007/may/16bschool.htm
Tsarafara, Madagascar
Tsarafara, near Mount Ibity in the Sahatany Valley of central Madagascar is a well known site that produces crystals of spodumene, morganite and tourmaline of various qualities. The miners use hand methods to find the crystals. Tsarafara is also known as Ankadilava or Ambalaroy in the literature. The colors of spodumene crystals from these mines may range from colorless to pale green, blue and pink. Top quality specimens are sold to collectors from around the world, and the rest are cut and polished at cutting centers in Southeast Asia and South Asia. The colors of tourmaline crystals may range from violet pink, green, dark green, bluish green to yellow, brownish yellow and near colorless. Top quality specimens end up with the collectors, while the low quality tourmalines are sold to African/Asian dealers for beads and carvings. The colors of Morganite crystals may range from pale to yellow orange color. Top quality specimens may show a pleasing orange pink to pink body color. Clean stones may yield beautiful faceted stones. As is the case with most low tech mines in Madagascar flooding during the rainy season can destroy the working mines.
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