Sapphire has different value factors than diamond. Communicating color and quality is much less standardized and can be subject to interpretation. For this reason, we deal only with the most reputable gem dealers. Sapphire is bought and sold primarily on color, but there are other important factors that affect rarity, and therefore, expense. A natural, sapphire that has not been enhanced in any way by heat or other treatments is very rare. It is estimated that over 95% of all blue sapphires traded are heat treated in some way. It is very common to expose sapphire crystals to high heat to affect a permanent change in color and/or clarity. In other instances, sapphire may be exposed to low routine heat simply to remove the host rock from the crystal after it is mined, not to improve its appearance. Although gemological laboratories may be able to detect evidence of heat, there is no way to know why it was used, therefore, any stone that shows evidence of heat is considered “heat-treated”.
There are also a number of other treatments widely used to improve the color and/or clarity of sapphire, including (but not limited to) lattice diffusion (heating to very high temperatures in the presence of a coloring agent), fracture filling with oil or epoxy, cavity filling with epoxy, resin, or glass, and irradiation. It is our policy not to deal in the sale or trade of treated sapphire, since the affected changes are not permanent with any of these treatments.
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