TOPAZ

The word topaz comes from the name of an island in the Red Sea, called "Topazes" in antiquity, and known today as the Zabrina. Previously, all yellow stones were considered topazes. It was not until the mid-18th century, thanks to the knowledge of its physical properties; we were able to distinguish it from other stones of the same color.

The yellow topaz is the best known of the general public. It is confused with Citroen, often fraudulently sold under names prohibited (Spanish topaz, Madeira, Rio ...). The real topazes are actually more expensive and less found in jewelry than we think at first glance.

The blue topaz is abundant on the market. Its light color is reminiscent of the finest aquamarines which it is often used as a substitute for affordable prices. Pink topaz is rare and is more expensive. It is usually found in antique jewelry.

The most productive deposits are in Brazil, Burma, Sri Lanka and Russia. Almost all are now treated to improve color: yellows turn pink when subjected to high temperatures, colorless take a deep blue when exposed to X-rays Most countries require that they have lost all trace radioactive before being sold on the market.

Characteristic

     Crystal system: Orthorhombic

     Chemical composition: Al 2 (SiO 4) (OH, F) 2 aluminum flu silicate

     Color: Colorless, yellow, orange-brown, blue, pink, green

     Hardness: 8.0

     Specific gravity: 3.52 - 3.56

     Refractive index: 1.61 - 1.64

     Dispersion: 0014

     Polychrome: Varies depending on color

     Birthstone: November