Jewels have been objects of desire from the earliest days of mankind. The enduring value of gems and pearls is largely a result of their beauty, durability and rarity. It is this last aspect that has pushed humans to create less expensive alternatives to the natural product. These include imitations such as glass, fully synthetic counterparts of natural gems and enhancements that modify gems and pearls to make them more valuable.
Certain enhancements have been practised for literally thousands of years. The dying of Agate is one example. Others, such as irradiated blue Topaz, are solely a product of the technological advances of the modern age. Enhancements often have an impact on the value of precious stones, with the highest prices paid for natural gems of fine quality that have not been enhanced in any way beyond ordinary cutting and polishing. As a gem is modified to a greater and greater degree, the change in value is also greater. The least expensive gems are those fully made by man (synthetics), because the supply is essentially unlimited. Thus they have limited or no rarity. What follows is a comprehensive description and discussion of enhancements.
Enhancement disclosure
Coloured Rocks takes enhancement disclosure seriously and, to the best of our ability, provides our clients with complete information on any and all enhancements to which a gem has been subjected. The descriptions we provide below are based upon those of the American Gem Trade Association guidelines (the most stringent in the industry). While many enhancements are currently undetectable, Coloured Rocks does its best to ensure that clients have full access to information for an informed buying decision.
Three ‘rules of thumb' for Gem Collectors
- For most gems today, enhancements are a basic part of the finishing process.
- The marketplace sets the values of both natural and enhanced gems.
- Since certain enhancements are undetectable or difficult to detect, the Coloured Rocks approach is to assume that all items are enhanced unless (There is specific gemological evidence that shows the item has not been enhanced or the item is of a type for which enhancements are not typically used.)
We do our best to describe our gems in a clear, consistent and honest fashion. Our approach is to give our customers the same information we would like if we were purchasing the piece. Our mantra is to be true both to our customers and to the precious stones with which we are privileged to work.
Treatment codes
One of the few problems or benefits (depending on your point of view) with the gemstone industry is that there is no single regulating body controlling its development. Cibjo (probably the largest jewellery trade organisations), the American Gem Trade Association (AGTA) and the International Coloured Stone Association (ICA) all got together in February 2010 and compiled a list of tag codes and descriptions for the disclosure of common treatments and enhancements. Although as yet, we haven't seen any other major retailer endorse these codes, as a company we believe it is a step in the right direction and have decided that in the future we will add these tag codes to all of the jewellery and loose gemstones that we sell.
Codes
| N | No modification (or currently has no known modification process) |
| H | Heating |
| O | Oil/Resin |
| W | Waxing |
| I | Impregnation (with colourless foreign substances other than oil/resin) |
| R | Irradiation |
| U | Diffusion |
| B | Bleaching |
| D | Dyeing |
| F | Filling |
| C | Coating |
| HPHT | High Pressure High Temperature |
In addition to the codes chart above, we have also decided to add three more codes; Re – for gems that are reconstituted; Db for doublets and Tr for triplets. Please note that often it is not possible to guarantee which treatments or enhancements have been applied to some gemstones. Some are very hard to detect and whilst we live in a world where corporations are driving out many small businesses, the gemstone industry remains one which is dominated by small artisanal miners (known in the trade as ASM's – artisanal small scale miners) and with around 80% of the worlds coloured gems supplied by ASM's, combined with the fact that 90% of them are in developing countries, it should be easy to appreciate that signed contracts and full disclosures are not something that is regularly available.
