This stone has been known for a very long time. The ancients (including Pliny the Elder) spoke of a gem called topazos {corresponding to our word topaz) which, from the description. appears to be olivine. This gem was called topazos because it came from an island in the Fled Sea named Topazos, now known as Zebirget. a fact which tends to confirm that it was indeed olivine. This is obviously one of those cases in which an old gem name has survived but has subsequently become attached to a different gem.

Appearance Typicaliy olive green. olivine can be a strong. almost bottle green, or yellowish green. In the gem trade, the greener type tends to be called |:-eridot. and the yellower type chrysolite. It has vitreous luster. Stones are usually transparent, with few inclusions and are given all types of mixed cuts. oval. round and pear-shaped, plus rectangular and square, step cuts. Gems of several carats are often seen, but very large stones are hardly ever found. Small stones are also cut and arranged in intricate patterns in jewelry.

Dlistinctive features The particular color and luster are highly characteristic. although some tourmalines. Zircons. and chrysoberyls may look much the same. A quick way of distinguishing them is by testing the density- Chrysoberyl and olivine also have very different refractive indices and chrysoberyl is usually more lustrous.

Occurrence The island of Zebirget still supplies excellent olivines, as it did in antiquity. Others come from the United States (Arizona), the Hawaiian islands, Burma, and Brazil.

Value Much appreciated in the past, olivine is the victim of changing fashions and is tar less highly prized today, Even exceptionally tine, large stones do not fetch very high prices and smaller ones are very low-priced.

Simulants and synthetics Olivine has been imitated by appropriately colored glass. synthetic corundum and syn thetic spinel. It has also been synthesized experimentally, but its low value has discouraged such attempts.