Treatments in the gem industry are common practice and are used to enhance the natural beauty of a gemstone. Treatments are an accepted enhancement as long as they are permanent and stable.
The most common form of gemstone treatment is heat treatment. Prior to being faceted, around 90% of all Corundum (Ruby and Sapphire) is heat-treated and when purchasing these gems, unless stated otherwise you should always expect them to be treated. Heat treatment is primarily used to enhance colour, and without heating some gem types would not exist. For instance, if we didn’t heat green-brown Zoisite we would not have Tanzanite! Heat treatment is considered totally acceptable, after all it is only carrying on what Mother Nature started.
Another treatment used, especially in Emeralds, is oiling; this is where colourless oil is used to penetrate voids and fissures. This does not harm the gem, although a treated Emerald will most likely have to be re-treated every ten years or so for it to continue looking ravishing.
Both of the treatments above are so widely used in the gem industry that it is common practice for them not to be disclosed. Therefore, when buying most gemstone varieties, it is best to assume that they have some form of treatment.
There are other types of treatments that are used within the gem industry: while several have been used for centuries, new technologies and treatments are continually being developed. Although it is globally accepted that it is not necessary to disclose heat treatment, or oiling or waxing of Emeralds, all other treatments such as dyeing gems (with the exception of Onyx which is always dyed) and coating gems should always be disclosed.
One of the newest and most exciting advancements in treatments is “Spice Topaz”. This revolutionary development offers new colours in Topaz that are both completely safe and completely permanent.
