Colorless zircon gemstones, which closely resemble diamonds, have been used as substitutes for the more precious look-alikes for more than one hundred years.  Those of Asian origin doubtless served as the huge “diamonds” that decorated the harnesses of ceremonial elephants in Oriental pageants.  It was not until the 1920s, however, that this versatile gemstone became truly popular.  Among the favorites for jewelry-making was blue zircon, which attained its fine blue hue through the process of heat treatment.  At the time, zircons discovered in what is now Cambodia were found to turn blue when subjected to heat.  Today, this perfectly acceptable process makes use of brown zircon from Thailand and Vietnam that is treated with heat until it shows a bright blue color.  Interestingly enough, blue zircon reheated in the presence of oxygen changes to golden yellow, another popular color for jewelry.

 

P.S.  Legends say zircon provides the wearer with wisdom, honor, and riches.