(via Roman Book On Precious Stones: 1950) Sydney H Ball writes:
Both the gem trade and the jewelry industry were made up of many small units producing, in most instances at least, individual orders. Mass production did not exist, the piece of jewelry being made and sold in the same shop. The customer might well furnish his gold and even his unset gems. Indeed, the client furnished the gold in Aristophanes time. Various lawsuits, however, show that some jewelers carried considerable stocks of gold and precious stones: some were men of wealth and from their tombstones we know they left large legacies and had many freedmen who served them. Of one such freedmen, Canuleius Zosimus, his patron, who erected the tablet, says: ‘He has never spoken evil of anyone and he did nothing contrary to the wishes of his patron. Though he always had much gold and silver in his possessions, he coveted none of it. He excelled in carving Clodian ware. A retail jeweler laments the death of this 13-year slave and in his epitaph he states:
‘Skilled was his hand in the art of finishing necklaces finely,
And to enclose in handwrought gold, bright glittering jewels.’
The tomb of Evodus, a pearl merchant (margaritarius) can be seen today on the Via Sacra. Most of the merchants were humble folk, but the epitaph of a woman dealing in pearls on the Via Sacra ‘had freedmen and freedwomen of her own,’ for whom she provided a last resting place beside herself.
Many of the gem engravers and lapidaries in Rome particularly after the reign of Augustus were of Greek origin, and frequently slaves. That the so-called Roman engraved gems were in many instances cut by Greek artists is indicated by the frequent use of Greek gods as subjects and the Grecian grouping presented. When the art passed largely into Roman hands, mere size was confused with beauty. Many wealthy Romans of the Late Empire had slave engravers in their homes. Further, it was not infrequent for a patron as a business venture to set up a skilled slave or freedman in the jewelry trade. However, slaves, in instances, saved enough to buy their freedom and as freedmen to finance their own shop. A Roman inscription at Malton, Yorkshire, England, mentions a goldsmith’s shop run by a slave, adding ‘good luck to you slave in running this shop.’
Gem engravers (gemmarii) cut either intaglios or cameos. The cutters of cameos were called caelotores or scalptores; while the artisans who fashioned the intaglios were known as cavatores or signarii. Lapidaries also cut cabochon stones and beads and polished smooth the natural faces of beryls and emeralds. Others fabricated false stones, some producing extraordinarily good imitations of certain gems. Each branch of the trade was handled by a specialist and Saint Augustine (354-430 A.D) compared the lesser gods with their circumscribed power with the craftsmen in the Streets of the Silversmiths, where each article passed through many hands, the mastery of the whole difficult to learn—that of the part, easy.
Guilds of artisans in the same trade must have originated in very early times (Babylonia long previous to 1900 B.C had had guilds) and they had some of the characteristics of our own labor unions; for example, Demetrius was perhaps the union leader of the guild of silversmiths in Ephesus. One of the oldest Collegia in Rome was that of the goldsmiths which is said to have existed in the time of Numa (715-673 B.C). Plutarch tells us that each guild had its own hall, its court, and its religious rituals peculiar to itself. By 150 A.D the guilds of the gold and silversmiths and of the salt miners were among the strongest in Rome. Caesar Augustus’ father was a silversmith. The silversmiths of Rome, as a body, erected (204 A.D) a small triumphal arch in honor of Septimus Severus and his family in the velabrum or cattle market where their shops were. Monsignor X Barbier du Montault gives an epitaph of a goldsmith who belonged to the guild in the time of Marcus Aurelius. In addition to the gold and silversmiths’ guilds there were ringmakers, goldbeaters, and gilders’ guilds.
These Latin guilds, like some of their successors of today, were politically minded. Scrawled on the walls of Pompeii we find, among other political propaganda, the following: ‘All goldsmiths recommend Gauis Cuspuis Pausa for the aedileship’.
In India, guilds are an ancient hereditary institution. The Ramayana or Ayodhya-Kanda describes a procession of trade guilds, jewelers, potters, ivory workers, perfumers, goldsmiths, and cutters of crystal. Among the Jews, unions did not exist before the Babylonian captivity. Some centuries later each guild had its appointed place and all members of the guild sat together in the huge synagogue at Alexandria, Egypt. The Egyptian goldsmiths in Christ’s time had their guilds.
Roman Jewelers And Lapidaries (continued)
Saturday, November 03, 2007
Million-dollar Outfits Worth Weight In Gold
Reuters Life writes about a Tokyo design school's (Bunka Fashion College) new concept: models decked out in more than 1,500 Austrian gold coins clinking down the catwalk + other viewpoints @ http://news.yahoo.com/s/nm/20071101/lf_nm_life/japan_dress_gold_dc
For Unsuccessful DTC Applicants: Sightholders Anonymous...
Chaim Even-Zohar writes about DTC's new sightholder support programme + the status of de-selected sightholders + the Avalon Project + other viewpoints @ http://www.idexonline.com/portal_FullEditorial.asp
Mogok, Burma
What is interesting is the way the Burmese King wanted to do business with the outside world . In my view, today's rulers aren't any different.
The government were provisionally continuing the old system which existed under the King of Burma. The rubies were dug by the natives who were licensed. They were bound to bring the rubies to a government officer, and record was made of all the stones. The person who dug the ruby estimated its value. If the government were satisfied with that valuation the digger had to pay one third of the estimated value to the government. If there was a dispute the government officer had a right to put a price upon it, and if that were not accepted the ruby was sent down to Mandalay and sold by auction.
The King theoretically had the right to purchase at market value all the stones above four carats in weight, but as a matter of fact very few of those stones ever got to him, as he could never give the fair value. A great many found their way to the dealers, and those that reached the concessionnaire, came to the markets of Europe. Ruby mines before the annexation of Upper Burma, had always been a sealed tract to European adventure and enterprise. No European was ever allowed to enter the forbidden region. There were no actual prohibitory orders, but there was a well-known disinclination on the part of the government, and that man’s perceptions would indeed have been dull who attempted to explore the country and expected to return. It was the policy of the Burmese government to conceal as far as possible from European eyes all appearances which would lead to a belief the Upper Burma was rich country which would well repay foreign conquest. Some years ago he said to the King who was then in want of money, that if he made concessions to trade with regard to overland route between Burma and China, money would flow into his country in equal volume with the waters of the great Irrawadi; but the King replied: ‘The money would come sure enough, but with it we should have a swarm of hungry European merchants and quarrelsome Indian natives, who would get into trouble with the people, and bring on complications which would eventually lead to the loss of the country. We would rather do without money, and keep our country.’ As soon as the disorganization set in, consequent on misrule, French intrigue took root at Mandalay, to the utter exclusion of British interests. A French consulate was established, and the government was asked to make certain concessions to French syndicates which if granted, would have imposed ruinous losses and conditions on the English commercial status in Lower Burma. One of those conditions involved a monopoly by France of the Ruby Mines district. The concession of the mines was actually contemplated at that time, but the contract was not approved and ratified by the King, and consequently was null and void.
As early as the 15th century, this country was known to produce rubies. Tavernier, a jeweler, who visited India in the middle of the 17th century, refers to Burma as yielding stones worth more than 100000 crowns a year, and that it is difficult to meet with one good quality weighing more than three or four carats, as the King kept all the larger. The largest stone of which any record seems to exist was 22 carats, and such stones are usually flawed.
Source: Anonymous
The government were provisionally continuing the old system which existed under the King of Burma. The rubies were dug by the natives who were licensed. They were bound to bring the rubies to a government officer, and record was made of all the stones. The person who dug the ruby estimated its value. If the government were satisfied with that valuation the digger had to pay one third of the estimated value to the government. If there was a dispute the government officer had a right to put a price upon it, and if that were not accepted the ruby was sent down to Mandalay and sold by auction.
The King theoretically had the right to purchase at market value all the stones above four carats in weight, but as a matter of fact very few of those stones ever got to him, as he could never give the fair value. A great many found their way to the dealers, and those that reached the concessionnaire, came to the markets of Europe. Ruby mines before the annexation of Upper Burma, had always been a sealed tract to European adventure and enterprise. No European was ever allowed to enter the forbidden region. There were no actual prohibitory orders, but there was a well-known disinclination on the part of the government, and that man’s perceptions would indeed have been dull who attempted to explore the country and expected to return. It was the policy of the Burmese government to conceal as far as possible from European eyes all appearances which would lead to a belief the Upper Burma was rich country which would well repay foreign conquest. Some years ago he said to the King who was then in want of money, that if he made concessions to trade with regard to overland route between Burma and China, money would flow into his country in equal volume with the waters of the great Irrawadi; but the King replied: ‘The money would come sure enough, but with it we should have a swarm of hungry European merchants and quarrelsome Indian natives, who would get into trouble with the people, and bring on complications which would eventually lead to the loss of the country. We would rather do without money, and keep our country.’ As soon as the disorganization set in, consequent on misrule, French intrigue took root at Mandalay, to the utter exclusion of British interests. A French consulate was established, and the government was asked to make certain concessions to French syndicates which if granted, would have imposed ruinous losses and conditions on the English commercial status in Lower Burma. One of those conditions involved a monopoly by France of the Ruby Mines district. The concession of the mines was actually contemplated at that time, but the contract was not approved and ratified by the King, and consequently was null and void.
As early as the 15th century, this country was known to produce rubies. Tavernier, a jeweler, who visited India in the middle of the 17th century, refers to Burma as yielding stones worth more than 100000 crowns a year, and that it is difficult to meet with one good quality weighing more than three or four carats, as the King kept all the larger. The largest stone of which any record seems to exist was 22 carats, and such stones are usually flawed.
Source: Anonymous
Friday, November 02, 2007
Inherit The Wind
(via YouTube): Inherit The Wind - Spencer Tracy Speech
http://www.youtube.com/watch?v=S_DQUAuNUvw
A real gem. One of my favorite movies.
http://www.youtube.com/watch?v=S_DQUAuNUvw
A real gem. One of my favorite movies.
Mali's Diamond-smuggling Centre
(via BBC Network Africa): Celeste Hicks writes about Mali's south-eastern town of Sikasso + the diamond smuggling network + other viewpoints @ http://news.bbc.co.uk/2/hi/africa/7071286.stm
(via FastCompany) Ellen McGirt writes about Facebook + the new business applications + building ecosystems that's business/user-friendly + other viewpoints @ Facebook is the "It" Company of 2007.
Useful link:
http://www.fastcompany.com/magazine/120/facebook-is-the-it-company-of-2007.html
Useful link:
http://www.fastcompany.com/magazine/120/facebook-is-the-it-company-of-2007.html
Museum Of Broken Relationships Opens
(via The Guardian) Kate Connolly writes about an interesting outlet for painful experiences - The Museum of Broken Relationships + other viewpoints @ http://arts.guardian.co.uk/art/news/story/0,,2201097,00.html
HINT: Avoid The Word ‘Nice’
Paul Gardner writes about the do's and dont's at art opening (s) + other viewpoints @ http://artnews.com/issues/article.asp?art_id=1437
Zambia And Gemstones
(via YouTube): Loose Gemstone Mining in Zambia, Africa
http://www.youtube.com/watch?v=hqybLjT5huM
It was educational.
http://www.youtube.com/watch?v=hqybLjT5huM
It was educational.
Roman Jewelers And Lapidaries
(via Roman Book On Precious Stones: 1950) Sydney H Ball writes:
Among the engravers’ tools were diamond splinters, set in iron, capable of cutting the hardest substances known: for softer stones emery or merely an iron point were used by engravers. The gem engraver also used the lima (or file) and in the bronze statue which Theodorus of Samos, architect, sculptor, and gem engraver, cast of himself, he holds a file in his right hand. He was one of the earliest gem engravers known, being mentioned by Herodotus. The file consisted of a mixture of emery and melted resin. Appuleius says that Hippias, the philosopher, used one in engraving the gem set in a ring which he fabricated for himself. Maecenas in a letter to Horace also mentions the lima. This is the forerunner of the diamond impregnated wheels and tools of today. The lapidary’s wheel with its accompanying drills was used by the Mesopotamian lapidaries in the 4th millenieum before Christ and reached Europe between 1800 and 1600 B.C (Minoan III period). The gravestone of a gem cutter found at Philadelphia, Asia Minor, in a broad way a contemporary of Pliny, shows what appears to be a bow drill. Doubtless some of the diamond splinters set in iron were used as tools in such drills. A Greek gem of the 5th century B.C now in the British Museum, also shows drilling. The Greek name for this type of artist, dacyloiloglyphos, is most descriptive, ‘he whose fingers hollow out the stone.’ The Roman lapidary also used a saw (serra) consisting of a wire drawn back and forth, fed with a powdered abrasive. The ostracious (perhaps flint) was also used to engrave gems. Whether the gem engraver used a magnifying glass is a moot question.
At first the worker in gold was called aurarius, later aurifex, and the retailer of rings, anularii. As to the setting of gems, Pliny says little. The beauty of the turquoise is, however, heightened by setting in gold, the contrast of the stone and the gold being admirable: a statement true today. The chrysolithos (topaz) if fine was set a jour in an open bezel, if of inferior quality its color was heightened by a foil of aurichalcium (a copper compound). The beauty of sarda (our carnelian) was, in some instances, increased by the use of silver foil and in others of gold. The art of the use of foils is an old one. The Minoans (2000-1600 B.C) made a gaming table decorated with strips and discs of rich crystal. The latter was alternately backed by silver plaques and blue vitreous paste (cyanos).
The Roman private banker, like the bankers of the Middle Ages, traded in precious metals and stones and usually also performed the functions of a dealer in gold and silverware. The Roman merchant was a greater traveler than his American confrere, a personal interview being required in many instances in which today a letter, a telephone call, a telegram, or a radio message suffices.
Like the people of the East, each trade in Rome tended to have its quarters. In 211 B.C, Hannibal was much annoyed when he pitched his camp on the Anio and found that in Rome the very land on which his tent was standing had since then been sold in Rome, with no reduction in price, so Livy tells us. Being at the city walls, he was so confident of the city’s fall that ‘in pique he bade an auctioneer put up the silversmith’s shops in the Forum for sale.’ The finest jewelry shops in Pliny’s time were in the great market buildings by the Saepta Julia on the Campus Martius, on the Porticus Argonautorum and the Via Sacra. On these Fifth Avenues of ancient Rome, one could purchase crystal cups, agate vases, and jewelry of every sort. We obtain an idea of the shops themselves from Martial, who describes Mamurra, a fourflusher, on a shopping tour in Rome. He examined everything. Next, complaining that some crystal vases had been spoiled by admixture of glass, he selected and set aside ten murrhine cups. He counted emeralds set in chased gold, and examined the largest pearl ear pendants. He sought on every counter for real sardonyxes and cheapened some large jaspers. At last when forced by fatigue to retire at the eleventh hour, he bought two cups for one small coin and carried them home himself. Many inscriptions have been found on the Via Sacra relating to tradesmen in luxuries, particularly jewelers. While the jewelers, engravers of gems, and lapidaries had workshops on the Via Sacra, much jewelry was imported from Asia Minor and from Alexandria, Egypt, while at least some of the cups of precious stones were cut in the East. Certain provincial towns were noted for their precious wares, Aquileia, for example, for its amber object d’art, its silverware, and its gold jewelry. Some twenty years ago there was excavated in the Via dell’ Abbondanza, Pompeii, the house of one Cerialis, a jeweler of Pliny’s time. In his flight from the terrors of the eruption he doubtless took with him his finest gems but a number of precious stones and some tools were left behind in his shop. In the dining room of the house of the Vettii in Pompeii is a most amusing mural depicting all phases of the jewelry trade. The proprietor, the artisans, and the grande dame client are all cherubs, entrancingly chubby, their absurdly small wings apparently too short for long distance flight.
Roman Jewelers And Lapidaries (continued)
Among the engravers’ tools were diamond splinters, set in iron, capable of cutting the hardest substances known: for softer stones emery or merely an iron point were used by engravers. The gem engraver also used the lima (or file) and in the bronze statue which Theodorus of Samos, architect, sculptor, and gem engraver, cast of himself, he holds a file in his right hand. He was one of the earliest gem engravers known, being mentioned by Herodotus. The file consisted of a mixture of emery and melted resin. Appuleius says that Hippias, the philosopher, used one in engraving the gem set in a ring which he fabricated for himself. Maecenas in a letter to Horace also mentions the lima. This is the forerunner of the diamond impregnated wheels and tools of today. The lapidary’s wheel with its accompanying drills was used by the Mesopotamian lapidaries in the 4th millenieum before Christ and reached Europe between 1800 and 1600 B.C (Minoan III period). The gravestone of a gem cutter found at Philadelphia, Asia Minor, in a broad way a contemporary of Pliny, shows what appears to be a bow drill. Doubtless some of the diamond splinters set in iron were used as tools in such drills. A Greek gem of the 5th century B.C now in the British Museum, also shows drilling. The Greek name for this type of artist, dacyloiloglyphos, is most descriptive, ‘he whose fingers hollow out the stone.’ The Roman lapidary also used a saw (serra) consisting of a wire drawn back and forth, fed with a powdered abrasive. The ostracious (perhaps flint) was also used to engrave gems. Whether the gem engraver used a magnifying glass is a moot question.
At first the worker in gold was called aurarius, later aurifex, and the retailer of rings, anularii. As to the setting of gems, Pliny says little. The beauty of the turquoise is, however, heightened by setting in gold, the contrast of the stone and the gold being admirable: a statement true today. The chrysolithos (topaz) if fine was set a jour in an open bezel, if of inferior quality its color was heightened by a foil of aurichalcium (a copper compound). The beauty of sarda (our carnelian) was, in some instances, increased by the use of silver foil and in others of gold. The art of the use of foils is an old one. The Minoans (2000-1600 B.C) made a gaming table decorated with strips and discs of rich crystal. The latter was alternately backed by silver plaques and blue vitreous paste (cyanos).
The Roman private banker, like the bankers of the Middle Ages, traded in precious metals and stones and usually also performed the functions of a dealer in gold and silverware. The Roman merchant was a greater traveler than his American confrere, a personal interview being required in many instances in which today a letter, a telephone call, a telegram, or a radio message suffices.
Like the people of the East, each trade in Rome tended to have its quarters. In 211 B.C, Hannibal was much annoyed when he pitched his camp on the Anio and found that in Rome the very land on which his tent was standing had since then been sold in Rome, with no reduction in price, so Livy tells us. Being at the city walls, he was so confident of the city’s fall that ‘in pique he bade an auctioneer put up the silversmith’s shops in the Forum for sale.’ The finest jewelry shops in Pliny’s time were in the great market buildings by the Saepta Julia on the Campus Martius, on the Porticus Argonautorum and the Via Sacra. On these Fifth Avenues of ancient Rome, one could purchase crystal cups, agate vases, and jewelry of every sort. We obtain an idea of the shops themselves from Martial, who describes Mamurra, a fourflusher, on a shopping tour in Rome. He examined everything. Next, complaining that some crystal vases had been spoiled by admixture of glass, he selected and set aside ten murrhine cups. He counted emeralds set in chased gold, and examined the largest pearl ear pendants. He sought on every counter for real sardonyxes and cheapened some large jaspers. At last when forced by fatigue to retire at the eleventh hour, he bought two cups for one small coin and carried them home himself. Many inscriptions have been found on the Via Sacra relating to tradesmen in luxuries, particularly jewelers. While the jewelers, engravers of gems, and lapidaries had workshops on the Via Sacra, much jewelry was imported from Asia Minor and from Alexandria, Egypt, while at least some of the cups of precious stones were cut in the East. Certain provincial towns were noted for their precious wares, Aquileia, for example, for its amber object d’art, its silverware, and its gold jewelry. Some twenty years ago there was excavated in the Via dell’ Abbondanza, Pompeii, the house of one Cerialis, a jeweler of Pliny’s time. In his flight from the terrors of the eruption he doubtless took with him his finest gems but a number of precious stones and some tools were left behind in his shop. In the dining room of the house of the Vettii in Pompeii is a most amusing mural depicting all phases of the jewelry trade. The proprietor, the artisans, and the grande dame client are all cherubs, entrancingly chubby, their absurdly small wings apparently too short for long distance flight.
Roman Jewelers And Lapidaries (continued)
Emerald Story
Historical significance
Emeralds are green gemstones colored by a trace of chromium, which belong to the mineral species called beryl. The name emerald is derived from the Greek word Smaragdos which in turn was derived from a Persian word. However, Smaragdos referred to all green gemstones at that time.
An interesting historical fact about emerald is that it was considered the symbol of immortality and faith, and was dedicated by the ancients to the goddess of love—Venus. It is even said to be beneficial to the eyes (this may be related to the fact that green in general has a nice soothing effect on the eyes). The greenery around us also helps to refresh our eyes.
Physical and Chemical properties of Emerald
Color: Emerald green, light green, bluish green, yellowish green and dark green.
Moh’s hardness: 7.5 Moh’s hardness measure’s a gemstone’s resistance to surface scratches. Gemstones with a hardness of above 7 are reasonably resistant to surface scratches, making them more durable. Durability is one of the most important attributes of a gemstone.
Specific gravity: 2.7-2.8. The specific gravity (SG) compares the weight of a gemstone with the weight of an equal volume of water at 4ºC. This means that emerald is approximately 2.7 times heavier than an equal volume of water at 4ºC.
Transparency: Transparent to opaque.
Refractive index: 1.57-1.59 (DR=0.006-0.008). The R.I of a gemstone compares the speed of light in air to the speed of light in the gemstone. The R.I of a stone can be measured with the refractometer.
Chemical composition: Al2Be3(SiO3)6 Aluminum beryllium silicate. The green color is imparted due to the presence of chromium and traces of iron darker this color.
Typical inclusions: Emeralds are characterized by inclusions such as liquid filled cavities, liquid filled cavities with gas bubbles (2-phase), liquid-filled cavities with gas bubbles and solid crystals (3-phase), solid inclusions such pyrite and calcite, surface reaching fissures and fissures often containing oil or resin, cloudy patches with liquid fingerprint inclusions. To the gemologist inclusions are regarded as flaws, but are evidence to the authenticity, or otherwise, of the stone. They also lend a unique exotic appeal to the stone, and have often been referred to as a jardin (or the emerald’s garden) by the experts.
Emerald formation and mining methods
Emerald belongs to the mineral species called beryl. Beryl in its pure form is colorless. When it acquires a green color owing to the presence of traces of chromium it is called emerald. Blue colored beryl is called aquamarine, pink color (less common) is called morganite, yellow is heliodor. Emerald (and other beryl) crystals mostly form within a hydrothermal environment when the elements, aluminum, beryllium and silica are present in the ideal amounts and combine in a chemical reaction to form crystals of beryl. When chromium is present the crystals acquire the rich green color of emerald. Beryl crystals are found within veins and embedded in the host rocks.
Mining methods
The mining methods employed for emeralds is still rather primitive. The tools commonly used are hand chisels, sickles, sticks and hammers to procure the stone from the host rock. Explosives are only used when absolutely necessary due to the very real danger such a practice might have on any fine (and valuable) crystals.
Two main mining methods are employed:
- Shaft mining / tunnel mining: Shafts and / or tunnels are dug in the ground and the gems procured.
- Terrace mining: Emerald bearing veins are exposed by digging horizontal terraces in step-like formation along gullies. The surrounding debris is washed away with water released from a lake like reservoir above the cuttings. The emeralds thus procured are washed and sorted into parcels.
Emerald (continued)
Emeralds are green gemstones colored by a trace of chromium, which belong to the mineral species called beryl. The name emerald is derived from the Greek word Smaragdos which in turn was derived from a Persian word. However, Smaragdos referred to all green gemstones at that time.
An interesting historical fact about emerald is that it was considered the symbol of immortality and faith, and was dedicated by the ancients to the goddess of love—Venus. It is even said to be beneficial to the eyes (this may be related to the fact that green in general has a nice soothing effect on the eyes). The greenery around us also helps to refresh our eyes.
Physical and Chemical properties of Emerald
Color: Emerald green, light green, bluish green, yellowish green and dark green.
Moh’s hardness: 7.5 Moh’s hardness measure’s a gemstone’s resistance to surface scratches. Gemstones with a hardness of above 7 are reasonably resistant to surface scratches, making them more durable. Durability is one of the most important attributes of a gemstone.
Specific gravity: 2.7-2.8. The specific gravity (SG) compares the weight of a gemstone with the weight of an equal volume of water at 4ºC. This means that emerald is approximately 2.7 times heavier than an equal volume of water at 4ºC.
Transparency: Transparent to opaque.
Refractive index: 1.57-1.59 (DR=0.006-0.008). The R.I of a gemstone compares the speed of light in air to the speed of light in the gemstone. The R.I of a stone can be measured with the refractometer.
Chemical composition: Al2Be3(SiO3)6 Aluminum beryllium silicate. The green color is imparted due to the presence of chromium and traces of iron darker this color.
Typical inclusions: Emeralds are characterized by inclusions such as liquid filled cavities, liquid filled cavities with gas bubbles (2-phase), liquid-filled cavities with gas bubbles and solid crystals (3-phase), solid inclusions such pyrite and calcite, surface reaching fissures and fissures often containing oil or resin, cloudy patches with liquid fingerprint inclusions. To the gemologist inclusions are regarded as flaws, but are evidence to the authenticity, or otherwise, of the stone. They also lend a unique exotic appeal to the stone, and have often been referred to as a jardin (or the emerald’s garden) by the experts.
Emerald formation and mining methods
Emerald belongs to the mineral species called beryl. Beryl in its pure form is colorless. When it acquires a green color owing to the presence of traces of chromium it is called emerald. Blue colored beryl is called aquamarine, pink color (less common) is called morganite, yellow is heliodor. Emerald (and other beryl) crystals mostly form within a hydrothermal environment when the elements, aluminum, beryllium and silica are present in the ideal amounts and combine in a chemical reaction to form crystals of beryl. When chromium is present the crystals acquire the rich green color of emerald. Beryl crystals are found within veins and embedded in the host rocks.
Mining methods
The mining methods employed for emeralds is still rather primitive. The tools commonly used are hand chisels, sickles, sticks and hammers to procure the stone from the host rock. Explosives are only used when absolutely necessary due to the very real danger such a practice might have on any fine (and valuable) crystals.
Two main mining methods are employed:
- Shaft mining / tunnel mining: Shafts and / or tunnels are dug in the ground and the gems procured.
- Terrace mining: Emerald bearing veins are exposed by digging horizontal terraces in step-like formation along gullies. The surrounding debris is washed away with water released from a lake like reservoir above the cuttings. The emeralds thus procured are washed and sorted into parcels.
Emerald (continued)
Tanzania And Tanzanite
(via YouTube) I found the video about Tanzania/tanzanite + the miners educational and interesting.
Part 1
http://www.youtube.com/watch?v=geQrt1LDvu8
Part 2
http://www.youtube.com/watch?v=NVb2WlKzfL0
Part 1
http://www.youtube.com/watch?v=geQrt1LDvu8
Part 2
http://www.youtube.com/watch?v=NVb2WlKzfL0
The Economic Way Of Thinking
Good Books: The book The Economic Way Of Thinking, by Paul Heyne + Peter J. Boettke + David L. Prychitko provides a set of economic principles and concepts--then applies these tools of analysis to a wide variety of familiar situations. Example (s) + Application (s) = Good teaching. A must-read book.
Here is what the description of book says (via Amazon):
The Economic Way of Thinking develops the basic principles of micro-and macroeconomic analysis, and rigorously employs them as tools rather than ends unto themselves. This book introduces readers to a method of reasoning; to think like an economist—teaching through example and application. It even teaches by showing learners how not to think, by exposing them to the errors implicit in much popular reasoning about economic events. Chapter topics include opportunity cost and the supply of goods, supply and demand, profit and loss, competition and monopoly, price searching, competition and government policy, the distribution of income, markets and government, the overall performance of economic systems, the supply of money, monetary and fiscal policies, national policies and international exchange, employment and unemployment, promoting economic growth, and the limitations of economics. For individuals seeking a deeper understanding of the effects of world events on the economy and vice versa.
Here is what the description of book says (via Amazon):
The Economic Way of Thinking develops the basic principles of micro-and macroeconomic analysis, and rigorously employs them as tools rather than ends unto themselves. This book introduces readers to a method of reasoning; to think like an economist—teaching through example and application. It even teaches by showing learners how not to think, by exposing them to the errors implicit in much popular reasoning about economic events. Chapter topics include opportunity cost and the supply of goods, supply and demand, profit and loss, competition and monopoly, price searching, competition and government policy, the distribution of income, markets and government, the overall performance of economic systems, the supply of money, monetary and fiscal policies, national policies and international exchange, employment and unemployment, promoting economic growth, and the limitations of economics. For individuals seeking a deeper understanding of the effects of world events on the economy and vice versa.
Thursday, November 01, 2007
The Art No One Sees
(via The Guardian) Robert Tait writes about Tehran's museum of contemporary art + cultural isolationist beliefs of the present regime + general clampdown on social, intellectual and cultural freedoms + other viewpoints @ http://arts.guardian.co.uk/art/news/story/0,,2201065,00.html
The New Visionaries
Barbara Pollack writes about contemporary artists vs. self-taught artists + the do-it-yourself style (s) + the outsider art concept (s) + other viewpoints @ http://artnews.com/issues/article.asp?art_id=1436
Reliance Jewelry India
It has been reported that Reliance Retail, part of Reliance Industries, the crown jewel of corporate India, will be launching Reliance Jewelry, with branding options + sourcing agreement with Rosy Blue, one of the largest jewelry manufacturers, for operations. It's part of the company's lifestyle retail concept, which includes books and music, cosmetics, lifestyle accessories and home solutions. According to consultants Technopak Advisors the Indian jewelry market + the branded jewelry is estimated to grow by 15 per cent + 30 percent annually.
Useful links:
www.ril.com
www.rosyblue.com
Useful links:
www.ril.com
www.rosyblue.com
Roman Jewelers And Lapidaries
(via Roman Book On Precious Stones: 1950) Sydney H Ball writes:
As to the cutting of gems, Pliny states that cut stones with a smooth level surface are preferred to those which exhibit depressions or other irregularities. An oblong shape is best; next to it, the lenticular; after this, circular stones are admired, those which are irregularly angular being held in the least esteem. In explanation, flat stones were preferred to those capable of being cut only cabochon, as the former were suitable for engraving. The oblong had evidently supplanted the ancient lenticular form while the angular was perhaps only used when to cut the rough gem in one of the more desired forms would drastically reduce the weight of a stone. The only stone Pliny mentions as faceted was the beryl (and its variety emerald) and this only by polishing the six faces of the natural prism; a method believed to be the best to increase the stone’s brilliancy. The Hindus, in Pliny’s stime, preferred long hexagonal beryl beads and these, pierced, were strung on elephant’s hair, it being the only stone they wore without gold setting. The piercing evidently improved the color adn transparency of some beryls although the finest were not pierced but were held in place by studs of gold attached to the ends. Beads of plasma and garnet also cut into prisms are from time to time found in Roman ruins, so abundantly indeed that graded necklaces can be made from them. These presumably postdate Pliny’s time. The sardonyx was also pierced and worn in neck ornaments by the poorer people of India. In Pliny’s time, the presence of a hole pierced in the stone proved it of Indian origin, an indication still in instances used by precious stone dealers. The lapidaries of the day hollowed out the lower side of garnets of deep color to give them a lighter and more pleasing hue. While shaped into cups, garnet ‘offers the most obstinate resistance to the graver’. Other stones were most easily cut, that of the callaina (turquoise) being ‘easily done’. Topazos (peridot) is the ‘only stone of high value that yields to the action of the file, the rest being polished by the aid of the stone of Naxos’ (emery). Peridot ‘wears with use’, its softness being the reason why we today rarely set it in rings. Unusually perfect rock crystals called acontetta (without flaw) were set uncut in jewelry.
Pliny states that the skilled artisan can hide the imperfections of rock crystal by cutting and engraving the stone. Tavernier, sixteen hundred years later, warned merchants to examine, with particular care, Indian diamonds with many facets, for the Hindu diamond cutter hid flaws with facets.
The garnets found on the hill of Orthosia in Asia Minor were cut ‘to perfection by the Alabandians’ in the nearby city of Alabanda. The early existence of this cutting center, exclusively for colored stones, is interesting.
Softer stones were shaped by a file but emery was used to cut and polish most gems. The emerald and the sapphire were rarely engraved and, as to the latter, the lapidary usually only polished the surface of the original pebble.
Pliny lists as famous engravers Pyrgoteles, Apollonides, Cronius, and Dioscurides, all Greeks. Alexander the Great permitted Pyrgoteles alone to engrave his likeness. Dioscurides cut a signet with an excellent likeness of Emperor Augustus, a seal thereafter used officially by the Roman Emperors. Gem engraving reached its height under Augustus adn continued on a high plane until the time of Hadrian when it began to deteriorate. Indeed, in general, the decline of classical art appears to have been more or less continuous from about 400 B.C to 200 A.D.
Seneca is the first Roman to speak of cameos (to be specific, a ring set with the head of Tiberius in relief), intaglios having preceded them by thousands of years. A few cameos, however, were cut in Greece and in Etruria early in the 5th century B.C but cameos only became relatively common a couple of centuries later when Indian layered stones were available to the Greek lapidaries. The Babylonians, centuries before, had rather crudely cut a few poor cameos. In Rome cameos which could only be used ornamentally, were never as popular as intaglios which were not only beautiful but also had their practical use as signets.
As to the cutting of gems, Pliny states that cut stones with a smooth level surface are preferred to those which exhibit depressions or other irregularities. An oblong shape is best; next to it, the lenticular; after this, circular stones are admired, those which are irregularly angular being held in the least esteem. In explanation, flat stones were preferred to those capable of being cut only cabochon, as the former were suitable for engraving. The oblong had evidently supplanted the ancient lenticular form while the angular was perhaps only used when to cut the rough gem in one of the more desired forms would drastically reduce the weight of a stone. The only stone Pliny mentions as faceted was the beryl (and its variety emerald) and this only by polishing the six faces of the natural prism; a method believed to be the best to increase the stone’s brilliancy. The Hindus, in Pliny’s stime, preferred long hexagonal beryl beads and these, pierced, were strung on elephant’s hair, it being the only stone they wore without gold setting. The piercing evidently improved the color adn transparency of some beryls although the finest were not pierced but were held in place by studs of gold attached to the ends. Beads of plasma and garnet also cut into prisms are from time to time found in Roman ruins, so abundantly indeed that graded necklaces can be made from them. These presumably postdate Pliny’s time. The sardonyx was also pierced and worn in neck ornaments by the poorer people of India. In Pliny’s time, the presence of a hole pierced in the stone proved it of Indian origin, an indication still in instances used by precious stone dealers. The lapidaries of the day hollowed out the lower side of garnets of deep color to give them a lighter and more pleasing hue. While shaped into cups, garnet ‘offers the most obstinate resistance to the graver’. Other stones were most easily cut, that of the callaina (turquoise) being ‘easily done’. Topazos (peridot) is the ‘only stone of high value that yields to the action of the file, the rest being polished by the aid of the stone of Naxos’ (emery). Peridot ‘wears with use’, its softness being the reason why we today rarely set it in rings. Unusually perfect rock crystals called acontetta (without flaw) were set uncut in jewelry.
Pliny states that the skilled artisan can hide the imperfections of rock crystal by cutting and engraving the stone. Tavernier, sixteen hundred years later, warned merchants to examine, with particular care, Indian diamonds with many facets, for the Hindu diamond cutter hid flaws with facets.
The garnets found on the hill of Orthosia in Asia Minor were cut ‘to perfection by the Alabandians’ in the nearby city of Alabanda. The early existence of this cutting center, exclusively for colored stones, is interesting.
Softer stones were shaped by a file but emery was used to cut and polish most gems. The emerald and the sapphire were rarely engraved and, as to the latter, the lapidary usually only polished the surface of the original pebble.
Pliny lists as famous engravers Pyrgoteles, Apollonides, Cronius, and Dioscurides, all Greeks. Alexander the Great permitted Pyrgoteles alone to engrave his likeness. Dioscurides cut a signet with an excellent likeness of Emperor Augustus, a seal thereafter used officially by the Roman Emperors. Gem engraving reached its height under Augustus adn continued on a high plane until the time of Hadrian when it began to deteriorate. Indeed, in general, the decline of classical art appears to have been more or less continuous from about 400 B.C to 200 A.D.
Seneca is the first Roman to speak of cameos (to be specific, a ring set with the head of Tiberius in relief), intaglios having preceded them by thousands of years. A few cameos, however, were cut in Greece and in Etruria early in the 5th century B.C but cameos only became relatively common a couple of centuries later when Indian layered stones were available to the Greek lapidaries. The Babylonians, centuries before, had rather crudely cut a few poor cameos. In Rome cameos which could only be used ornamentally, were never as popular as intaglios which were not only beautiful but also had their practical use as signets.
Gem Markets
Gem markets have unique rhythms. One quality the market shares with music is the mother-of-all-surprise (s). Music giants like Bach, Mozart, Beethoven were masters of deception and expert at weaving rhythms across bars. Look what's happening in the diamond, ruby and sapphire + emerald market (s). The migration of market (s) + sequences = shortage of good quality gemstones.
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