Learning Library


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.

Back to Learning Library

Moonlight Quartz is Quartz which has been treated.