Evidence of the gemstone trade dates back seven thousand years. But it is only since medieval times that trade in gems became organized and secretive. Secrets of the trade were passed on from generation to generation and are still evident today. It was essential for merchants to guard the source of their precious finds as a matter of self preservation. Today, the gemstone trade is a closed fraternity based on high levels of trust between members. Trust is the cornerstone of the professional jewellery and precious stone business. As a gem buyer, I depend on honest information from trusted dealers with a gemological background. But in a world of enticing colours and glitter the paths are fraught with deception and misrepresentation.
Just as in any other field, human ingenuity has entered the realm of gemstone enhancement, by artificially improving the appearance of the natural crystal. Heating and or irradiating certain stones to saturate the colour may increase their values, while an untreated naturally beautiful sapphire or aquamarine will be traded at a premium. Industry standards mandate full disclosure of any enhancement a stone had been subjected to. This transparency is vital to the trade, from the gem dealer down to the client adoring an original piece created with precious gems.
It is fascinating we value coloured rocks, formed in the earth’s crust over thousands/millions of years of heat and pressure. Our lust for these sparkling beauties goes far beyond the physical properties we endear. Gemstones, in particular coloured gemstones, also boast the attribution of rarity and healing power.
Precious stones are graded for value by a set of criteria known as the 4C’s: cut, colour, clarity and carat weight. One could arguably add the characteristic of rarity to this formula. Alexandrites in the desirable qualities of size and degree of colour change are very rare as is a certain tourmaline from a now closed mine in Paraiba, Brazil.
While the business behind the gemstone trade is intriguing, our imagination is very much captured by the beauty and brilliance each coloured crystal holds. Bringing this magic to light is the work of a very experienced lapidary (gem cutter), trained in various crystal systems and physical properties. This vast knowledge combined with the precise faceting skills transforms a dull raw crystal into a deeply rich gemstone. All this work is still done by hand–very skilled hands and eyes to preserve the integrity of the most valued gems. One of these centres of highly trained professionals is Idar-Oberstein, a small town in southwestern Germany. Despite economic pressures, Idar is still home to many multi-generational lapidary shops.
Contemporary lapidaries are constantly pushing the boundaries of what has been a very traditional trade. Creativity and the advent of computer applications have helped bring very effective new facet designs to light. One pioneer in creating new gemstone designs is Bernd Munsteiner of Idar-Oberstein. Starting in the early eighties, Munsteiner broke with tradition by developing what he called the “fantasy cut”, carving strategically placed facets into the back of a gemstone. The result is a spectacular light-show appearing in the front.
While the cut of a stone describes the geometry and placement of facets, the shape refers to the actual outline. The shape of gemstones plays a dominant role in any jewellery design, the inspiration for the next creation. Classic shapes like round, oval and teardrop top the list, followed by emerald cut, square and cushion. The curved triangular form called trillion is considered one of the fancy cuts and is very versatile in jewellery design.
Colour may be the other preferred criteria when choosing a stone, as colour has the power to evoke deep emotional reactions. Red, blue and yellow are primary unmixed pure hues. Secondary hues like green, violet and brown are the result of mixing two or more primaries. Hue, saturation and tone are the three components what we commonly perceive as colour. Hue is technically the colour, saturation refers to the brightness of the hue, either vivid or dull. Tone, the third component describes the hues lightness or darkness. Balancing the three factors in a gemstone creates the beauty we desire and love.
The third “C” describing clarity is easily understood, as it indicates the level of blemishes or fractures contained within a crystal. Inclusions of any kind reduces the amount of light refracted and thus the stone will appear less brilliant. On the flip side, inclusions can be used creatively as a feature in the stone design by a gem cutter.
A few lesser known facts about gemstones:
Sapphires are second only to diamonds in hardness and come in most hues of the colour spectrum.
- A red sapphire containing a trace amount of chromium in its mineral composition is considered a ruby.
- Emeralds and aquamarine are members of the beryl family. Also included in this group are red beryl, yellow (heliodor) and morganite.
- Alexandrite is a chrysoberyl that has aluminium replaced by chromium. This composition enables the rare stone to change colour from emerald green in daylight to a strong purplish red in incandescent light.
- Spinel gained prominence when in the 19th century it was discovered that the Black Prince’s ruby was actually a superb red spinel. The stone is now part of the British Imperial State Crown.
Working with these fine gifts from deep inside the earth is exhilarating and a privilege. I believe each precious stone should be honoured by creating a piece of jewellery of lasting value that can be treasured for generations.