Jean-Baptiste Tavernier’s Travels In India

Concerning Diamonds, And The Mines And Rivers Where They Are Found; And Especially Of The Author’s Journey To The Mine Of Rammalakota
(via Jean-Baptiste Tavernier’s Travels In India / V Ball / Edited by William Crooke)

The diamond is the most precious of all stones, and it is the article of trade to which I am most devoted. In order to acquire a thorough knowledge of it I resolved to visit all the mines, and one of the two rivers where diamonds were found; and as the fear of dangers has never restrained me in any of my journeys, the terrible picture that was drawn of these mines, situated in barbarous countries to which one could not travel except by the most dangerous routes, served neither to terrify me nor to turn me from my intention. I have accordingly been at four mines, of which I am about to give descriptions, and at one of the two rivers whence diamonds are obtained, and I have encountered there neither the difficulties nor the barbarities with which those imperfectly acquainted with the country had sought to terrify me. Thus I am able to claim that I have cleared the way for the others, and that I am the first European who has opened the route for the Franks to these mines, which are the only places in the world where the diamond is found.

The first of the mines which I visited is situated in the territory of the King of Bijapur in the Province of Carnatic, and the locality if called Rammalakota, situated five days journey from Golkonda, and eight or nine from Bijapur. The fact that the two Kings of Golkonda and Bijapur were formerly subject to the Mogul, and were then only Governors of the Provinces which they acquired by their revolt, caused it to be said, and to be still said by some people, that the diamonds come from the Empire of the Great Mogul. It is only about 200 years since this mine of Rammalakota was discovered, at least so far as I have been able to ascertain from the people of the country.

All round the place where the diamonds are found the soil is sandy, and full of rocks and jungle, somewhat comparable to the neighborhood of Fontainebleau. There are in these rocks many veins, some of half a finger and some of a whole finger in width; and the miners have small irons, crooked at the ends, which they thrust into the veins to drawn from them the sand or earth, which they place in vessels; it is in this earth that they afterwards find the diamonds. But as the veins do not always run straight, as some ascend, while others descend, they are obliged to break the rocks, always following the direction of the veins. After they have opened them out, and have removed the earth or sand which may be in them, they then commence to wash it two or three times, and search it for whatever diamonds it may contain. It is in this mine that the cleanest and whitest-watered diamonds are found; but the evil is that in order to extract the sand more easily from the rocks the miners strike such blows with a heavy iron crowbar that it fractures the diamonds, and gives rise to flaws. This is the reason why so many thin stones come from this mine, for when the miners see a stone in which there is a flaw of some size, they immediately cleave it, that is to say split it, at which they are much more accomplished than we are. These are the stones which we call thin (foible), which make a great show. If the stone is clean they do not do more than just touch it with the wheel above and below, and do not venture to give it any form, for fear of reducing the weight. But if it has a small flaw, or any spots, or small black or red grit, they cover the whole of the stone with facettes in order that its defects may not be seen, and if it has a very small flaw they conceal it by the edge of one of the facettes. But it should be remarked that the merchant prefers a black point in a stone to a red one. When there is a red one the stone is roasted, and the point becomes black. I learned this trick at length so well that when I examined a parcel of stones which came from this mine, and saw that there were facettes on any of them, especially small facettes, I was certain that there was some speck of flaw in the stone.

There are at this mine numerous diamond cutters, and each has only a steel wheel of about the size of our plates. They place but one stone on each wheel, and pour water incessantly on the wheel until they have found the ‘grain’ of the stone. The ‘grain’ being found, they pour on oil and do not spare diamond dust, although it is expensive, in order to make the stone run faster, and they weight it much more heavily than we do.

Jean-Baptiste Tavernier’s Travels In India (continued)

Spain Shown Perils Of Climate Change

(via The Guardian) The images from the book 'Photoclima' via Greenpeace is quite shocking. What will be the fate of cities like Dubai, Singapore, and other coastal cities in the coming decades? Frightening and nowhere to run!

Useful link:
http://www.guardian.co.uk/environment/2007/nov/10/flooding.climatechange

Madagascar

(via Wikipedia) Madagascar, or Republic of Madagascar (older name Malagasy Republic), is an island nation in the Indian Ocean off the southeastern coast of Africa. The main island, also called Madagascar, is the fourth largest island in the world, and is home to five percent of the world's plant and animal species; more than 80 percent of which are endemic to Madagascar. Most notable are the lemur infraorder of primates, the carnivorous fossa, three endemic bird families and six endemic baobab species + the entire country is rich in colored gemstones.

Useful links:
http://en.wikipedia.org/wiki/Madagascar
http://www.lonelyplanet.com/worldguide/destinations/africa/madagascar

Enrico Caruso

Enrico Caruso was an Italian opera singer + one of the most famous tenors in history. I enjoy the music + listening to Caruso's songs + his extraordinary voice + the natural tone is inspirational and therapeutic. He was a superstar of his time but the music still lives on.

Enrico Caruso songs:
La donna è mobile
Ave Maria
Vesti La Giubba
No Pagliaccio non son
La Partida
O Sole Mio
Santa Lucia

(via Henry Rosner) Hear Enrico Caruso sing Vesti la giubba from "I Pagliacci, Act 1" 17 March 1907 (in mp3 format)

More information about Enrico Caruso's recordings @ Enrico Caruso recordings.

The Emerald Story

The main cuts employed for emeralds

Step/Emerald cut: This is the most important and popular cut employed for emeralds. All facets are cut in squares or rectangles which are arranged in steps, giving an elongated octagonal outline. The best quality emeralds are almost universally fashioned in this way for these reasons:
- It shows the saturated deep velvety-green of emerald to the best advantage. Since color is the most important determinant of value in emeralds, a stone with a good depth of color fetches a higher market price than one that does not.
- The step cut minimizes loss of mass during cutting and polishing. This means more carat weight retention of the stone and hence value (value = price/carat x carat weight).

Mixed cut: The crown of the stone is brilliant cut, while the pavilion is step cut. It is not very popular since it gives the stone a pale glassy look, which is not desirable.

Cabochon & beads: Stones which are turbid and heavily included and are of good color are commonly cut as cabochons and beads. A cabochon may have a flat base and a dome-shaped upper portion. Emeralds cut in this manner are usually sub-transparent to opaque, and can range from light to very dark green. Emeralds of low to medium quality are thus fashioned. Emerald beads and cabochons are becoming increasingly popular since they are a beautiful yet inexpensive form of natural emeralds.

Fancy cuts and carvings: Heavily included emeralds with good color but limited transparency are an excellent base for carving. Carved emeralds are fashioned into pendants, belt-buckles, and show pieces in a variety of exotic jewelry.

The cut of a stone is crucial to its color and beauty, and has great influence on its ultimate value.

Common treatments applied to emeralds
Mining, cutting, faceting, and polishing procedures are accepted and considered, as the normal processing of gemstones. However, in his endeavor to enhance value, man has subjected his gems to further treatments. Some of the treatments are necessary and are now accepted as normal processing for a gemstone, while others are subject to disclosure.

The common treatments for emeralds are oiling, staining/dyeing and resin impregnation.

Oiling: Perhaps the most universal treatment for emeralds, practised by emerald dealers all over the world. This treatment is more of a finishing touch applied to emeralds of good color but with visible internal fissures. Oiling enhances surface shine and luster, and reduces the visibility of fissures in the stone, thereby adding to its saleability.

Oils used: Cedarwood oil, Canada Balsam, mineral oil.

Method: The method of oiling varies from dealer to dealer, with much being kept secret for obvious reasons. But basically, it involves these steps: (a) Emeralds are first cleaned thoroughly using a mild acid (b) They are then soaked in warm clear oil (Cedar oil is popular) and subjected to appropriate heat and sometimes pressure or vacuum.

Effect: The oil permeates into the fissures and fills them, reducing their visibility. Modern oiling machines offer an easily and effective treatment method for emeralds.

Durability of treatment: The oil comes out of the fissures when subjected to heat, ultrasonic cleansing, immersion in soapy water or acids, alcohol or other solvents. Otherwise, for normal wear and tear, it remains stable for a reasonable period of time. Stones can be re-oiled if necessary.

The practice of oiling is so prevalent that it is hard to curb. It is regarded as standard practice. But since the effect is not 100% permanent, trade organizations and gem testing laboratories encourages disclosure of the treatment to customers upon purchase.

Detection of oiling under the microscope: Traces of oil may be seen in fissures when the stone is viewed under the microscope. Typical signs of oiling are:
- Low relief of fissures that would otherwise appear white. Some fissures tend to appear shiny (fluid-like) when viewed at certain angles.
- Flattened gas bubbles trapped in the filling media (oil)
- Some oils fluoresce (emit light) when subjected to ultra-violet (UV) radiation. For e.g. Canada Balsam shows a weak greenish yellow light under UV.

Staining/dyeing: Yet another age-old technique to enhance the appearance of a gem that is commonly applied to emeralds. Whereas the main motive for oiling an emerald is to conceal fissures, the main aim of dyeing an emerald is to give a false appearance of color in otherwise pale-colored emeralds. The dyeing of colorless beryl to simulate the appearance of emerald is also carried out. Staining or dyeing may be either a surface only treatment or it may penetrate fissures.

Dyes used: Natural organic dyes, synthetic dyes (e.g. aniline) compounds of metallic salts.

Method: (a) The stone is thoroughly cleaned. (b) The stone is soaked in oil containing the green dye at an appropriate temperature for a few hours.

Effect: The green oil permeates into the stone increasing depth of color, and reducing the visibility of internal fissures.

Durability of treatment: Natural organic dyes are least stable and some deteriorate easily. Synthetic dyes tend to last longer. Certain dyes don’t come out of the fissures even if the oil wears off when subject to heat or alcohol.

Status of treatment: Since dyeing significantly alters the appearance of emeralds and possibly other beryls and is not permanent, this treatment should be disclosed to customers upon purchase.

Detection of treatment: One can always detect the presence of dye under magnification. Indications are: (a) Color concentration in fissures and chips, (b) Slightly colored outlining of fissures, (c) Uneven color distribution, (d) Some colored oils fluoresce under UV radiation.

Resin impregnation of fissures (Opticon treatment): A relatively recent development in the treatment of emeralds. It involves impregnating fissures with a synthetic resin marketed as Opticon. Opticon, as a resin, is more durable than oil, making the treatment more permanent. It is a two part product consisting of the resin itself plus a separate hardener (an additional fluid which when added to the resin causes it to become hard). A vacuum is usually used to assist the flow of the resin into the fissures in emerald. Sometimes the treater will then add the hardener and sometimes not.

Detection of the treatment: Many resins, including Opticon can be detected by the observation of blue and yellow/orange color flashes coming from the region of treated fissures. Positive identification can come from Raman spectroscopy available only in the best equipped gem labs.

Status of treatment: If no hardener is applied, whilst this resin treatment might be a little more stable than oiling it is still not permanent. If a hardener is applied this may cause fissures to expand under warm conditions, or when being repolished, which may result in severe damage-occurring. Hence, disclosure of treatment is required.

Emerald Story (continued)

Memories Of Spain

(via The Guardian) James Fenton writes about the Hispanic Society of America, on West 155th Street in Manhattan (USA) + Archer Milton Huntington + his passion + other viewpoints @ http://arts.guardian.co.uk/art/visualart/story/0,,2204239,00.html

The Real Thing?

Ann Landi writes about contemporary realism + handful of mature artists pursuing realist idiom of one stripe or another + the impact + other viewpoints @ http://artnews.com/issues/article.asp?art_id=1150

The Burgundian Point Cut

(via Diamond Cuts in Historic Jewelry:1381-1910) Herbert Tillander writes:

A Refined Dodecahedron
In the days when superstition prevailed, a cutter could evade the strict rules which controlled the shapes of fashioned diamonds if he had a particularly well developed dodecahedron at his disposal. The four rhombic faces of such a crystal, chosen to face the viewer, could be smoothed and polished at a minimal angle of inclination, thus preserving the shape of a natural crystal.

Crystals fashioned in this way, side by side with Pyramidal Points and Table Cuts, were entirely acceptable and considered ideal as talismans. The Court Goblet of the Duchy of Burgundy in the Vienna Hofburg, with its numerous early and mid-fifteenth century diamonds, is our foremost source of information on cuts of the period. It also indicates that fashioning had been fully mastered by then.

The majority of the larger diamonds display brilliance in the modern sense of the term. This means that by the early fifteenth century cutters had discovered the property inherent in diamonds of reflecting the rays of light from pavilion facets set at correct angles of inclination. Fortunately for posterity, princes of refined taste appreciated these sparkling qualities of diamonds, although at the time fashion still demanded pyramidal shapes and Table Cuts, disapproving of brilliance.

The Burgundian is also exceptional in that it became a prototype which could, simply by means of additional faceting, be transformed into a number of other patterns: the Pointed Star, the Taille en Seize, and finally the Baroque type of Brilliant cut. It was also economical, since it could be fashioned on the wheel alone, and therefore with comparatively little loss of weight.

At first, the pavilion did not differ very much from the crown, but when strictly crystal-like shapes were no longer challenged, the cutters were free to fashion the pavilions differently—depending, of course, on the symmetry of the crystal and the presence of disturbing inclusions in the lower part of the gem.

As a rule, natural dodecahedrons have distinctly rounded faces and sharp, curved edges. Symmetrization of these faces presented no problems to the cutters. The corners were frequently left blunt and were partly hidden by the setting, so that regular crystals could be made to appear almost perfectly round or oval or lozenge-shaped. They were about 25 per cent lower than Pyramidal Point Cuts, but looked lower still because of their semi-spherical appearance. In addition to an amazing amount of brilliance, many of the fashioned gems also displayed fire. Easily identified in contemporary inventories, they are frequently described as having four main lozenge-shaped facets in the center, surrounded by eight semi-lozenges—i.e. Lozenges split into two triangles. In many cases they are described simply as faceted diamonds with an adjective indicating the outline.

As the fashion for Table Cuts (both traditional and more exotically faceted) grew, the apexes of many Burgundian Cuts were ground down. Later, most of the remaining stones of this type were re-cut, the larger sizes into Baroque Brilliants and some smaller ones into matching complementary Double Cuts. This explains why so few Burgundian Point Cuts have survived in their original form.

Fortunately, there are two on the Burgundian Court Goblet. The larger gem, which is about 8.7 mm in diameter, is in a separate setting. In 1621 it was described as ‘Ain Diamant spitzig sternweiss geschnitten (a pointed diamond cut like a star)’. The smaller gem, about 5 x 3 mm in size, forms part of a fleur-de-lis.

An illustration by an artist from Basel, drawn in about 1500, shows a Burgandian Cut on another famous jewel belonging to Charles the Bold, the Feather, thought to have been made in the 1460s. The stone, which must have been about 12.5 mm in diameter, with a weight of about 6 ct, can be seen very clearly in the sales document drawn up between the City of Basel and Fugger’s, and was described as ‘ein demant mit faceten, gutt wasser, nit rein, vol swartzer bunten’.

There is one other illustration of a jewel covered with diamonds of this type. This is a sketch drawn, according to Erna von Watzdorf, by G.C Dinglinger, the less talented brother of the famous Johann Melchior Dinglinger. The drawing is said to date from as late as 1719, when this type of cut was already out of fashion.