Topics: Value of Dyed, Heated or Stabilized Gemstones
Are dyed, heated or stabilized gemstones less valuable than the natural ones? And what is the difference between them?
It depends on what you're comparing. If you're comparing a dyed or heated A grade citrine cabochon to a natural A grade citrine cabochon, then the dyed or heated cabochon will be less valuable than the natural one. This is only true if the only difference between the two cabochons is that one is dyed or heated and the other is natural and that--in all other ways, like color and clarity--they're the same quality. Most stones are treated in some way, as they would not be stable enough for use in jewelry in their natural state; turquoise is a good example.
You can find information regarding enhancements for gemstone beads and cabochons in the ''Gemstone Treatment Guide''. There are many different types of stone grading systems in the world today. There are well established and respected standards for diamonds; however, there are few accepted and respected standards for other gemstones. The ''Gemstone Treatment Guide'' was developed by the American Gem Trade Association (AGTA)--of which Fire Mountain Gems is a charter member--to encourage enhancement disclosure in the gemstone trade. The AGTA scale starts with 'A' as the highest quality and works down the alphabet as the quality decreases (so a 'B' grade emerald will be more valuable than a 'D' grade emerald).
A gemstone is considered dyed, by AGTA guidelines, when coloring matter has been introduced into the stone to give it new color, intensify its present color or improve its color uniformity. According to AGTA, a gemstone is considered heated when heat is used to create a change in color, clarity and/or phenomena. A gemstone is considered stabilized when a colorless bonding agent (commonly plastic) is used to give a porous gemstone added durability and improve its appearance.
For information about specific gemstone materials, see our Gem Notes information section. It contains images of a wide selection of gemstones and includes design possibilities, gemstone histories and believed metaphysical properties for your convenience.