Topaz

Topaz - (Easton's Bible Dictionary)

Heb. pitdah (Ezek. 28:13; Rev. 21:20), a golden yellow or "green" stone brought from Cush or Ethiopia (Job 28:19). It was the second stone in the first row in the breastplate of the high priest, and had the name of Simeon inscribed on it (Ex. 28:17). It is probably the chrysolite of the moderns.

Topaz - (Webster's 1828 Dictionary)

TO'PAZ, n. [Gr.] A mineral, said to be so called from Topazos, a small isle in the Arabic gulf, where the Romans obtained a stone which they called by this name, but which is the chrysolite of the moderns. The topaz is of a yellowish color. It sometimes occurs in masses, but more generally crystallized in rectangular octahedrons. Topaz is valued as a gem or precious stone, and is used in jewelry. It consists of silex, fluoric acid and alumin, in the following proportions; alumin 57 parts, silex 34, and fluoric acid 7 or 8.

Of topaz there are three subspecies, common topaz, shorlite and physalite.