OLD CUT
Also sometimes referred to as ‘old European cuts’, old cut diamonds are characterised by a symmetrical rounded outline, and a deep crown and pavilion (the top and bottom sections of a brilliant cut stone when viewed in profile). Though they existed as early as the seventeenth century, they did not reach the height of their popularity until the late nineteenth century.
This was largely due to two men in the United States, Henry D. Morse and Charles M. Field. In 1874 they patented a steam driven bruting machine–bruting being the term for the process by which the outline of a diamond is fashioned during the cutting process. Morse was a diamond cutter, and was the first to utilize this invention to create rounded symmetrical stones with newfound relative ease.
Not only did it allow diamonds to be cut more easily, the invention coincided with an influx of diamonds into the world market, with the discovery of the gems in South Africa in 1867. The downside to this cut, which is in part why it was avoided in the past, is the inevitable loss of weight, which would otherwise be retained when sticking more closely to the squared shape of a natural rough diamond, as in table and old mine cuts.
However, another machine–the power-driven circular saw–invented around the same time, made it possible to cut a diamond and retain the excess, which could then be cut into smaller diamonds, rather than grinding the excess into diamond dust, as was done in the past. As a result of these three converging factors, this cut soon became the new standard, largely replacing the cushion shaped old mine diamond. The cut remained popular well into the mid-twentieth century, and are today a much-loved feature of antique and vintage jewellery.
OLD MINE
The term ‘old mine’ refers to gemstones deriving from historical, often ancient, mining sources.
With regards to diamonds, for example, this would indicate that the stones were mined in India or Brazil, the two primarily mining locales prior to the discovery of diamonds in South Africa in the late nineteenth century. India in particular is renowned for diamonds mined in the central area of the subcontinent surrounding the city of Golconda, and are known for their particularly high quality in terms of size, colour and clarity. The Hope diamond and the Koh-i-Noor, perhaps the two most famous diamonds of all time, are Golconda diamonds. To add to the rarity of such stones, these mines have been largely exhausted.
In the case of emeralds, stones classified as old mine would be from Egypt, Austria, Gandahara (the ancient central Asian kingdom) or, primarily, Colombia. The highest quality old mine emerald material derives from this last source, which had been mined by pre-Colombian tribes for approximately one thousand years. It was not until the Spanish presence in the New World in the early sixteenth century, however, that these stones graced the royal courts of Europe, the Middle East, and, primarily, India.
OPAL
According to the Australian aboriginies–Australia being the preeminant source of opals–the gems are the physical manifestation of a rainbow that brought peace to all humans.
Precious opals display an optical effect called ‘play of colour’ or ‘fire’. This is due to a combination of different factors. Opal is composed of a stacked framework of silica spheres, and it is the diffraction and interference of light between these spheres that create the fascinating colour play. The colours produced depend on the size of these spheres. A whole spectrum of colours can be seen in the most desirable opals. The play of colour shimmers with iridescence across the stone and is distinctive of these beautiful gems.
Opals occur in a range of body colours from white, black or grey, bright orangey red and a pale watery colour. The most precious opals show strong colour contrast and generally have a dark body colour with a vivid array of colour play. They are usually cut en cabochon which displays their optical effect beautifully and is also the best shape for their hardness.
In Roman times opals were mined in Czechoslovakia, and continued for centuries to produce white opals, prior to the discovery of the world’s main source for opals, Australia. Australia is famous for its opal production of the most vivid colours and occurs in many localities. In 1903 black opal was found in Lightning Ridge in north-east New South Wales, which is now one of the most famous areas for precious opals in the world. An opal weighing 203 carats was found in Andamooka, Australia, in 1949 and was set into a necklace presented to Queen Elizabeth II. Mexico is another major source for opals, especially for fire opal of a strong red / orange body colour.
OSCAR HEYMAN
The firm of Oscar Heyman & Brothers was founded in 1912 in New York City, and since its inception has been a manufacturer of handmade jewellery of the finest quality. With no obvious prospects in their native Latvia, Oscar (b. 1888) and Nathan Heyman (b. 1885), thirteen and sixteen years of age respectively, left home to become apprentices with their uncle at the famous Fabergé workshop in St Petersburg, Russia. In 1906 they fled Russia to avoid conscription into the Imperial Army and moved to New York City. Oscar then worked for Pierre Cartier who was just starting Cartier, New York. With skills learned from these top jewellers, Oscar and Nathan, soon joined by other members of the family, formed the company we know today as Oscar Heyman & Bros.
The firm’s exacting craftsmanship was contracted out to other jewellers of great renown with Cartier as their first customer, and a list which was soon to include Van Cleef & Arpels, Tiffany & Co, Bailey Banks & Biddle, and Marcus & Co to name a few. For example, the world may think that Cartier made the necklace upon which hung the famous D flawless, 69.42 carat Taylor-Burton diamond, but if was in fact Heyman. There is a cachet to owning an Oscar Heyman piece, as the attention to detail and fine quality of materials is ‘de rigueur’ for the firm. They are the jeweller’s jeweller, and are only recently being recognized for their lasting contribution to jewellery history.