The variety used for gemstones is a hard, transparent, crystalline mineral composed of aluminum fluosilicate. It is harder than quartz and is often found in cavities of granitic rocks. Topaz may be colorless, but it also occurs in a great range of colors that include white, yellow, light brown, pinkish red, and sometimes pale green or blue. The most popular shade is wine-yellow. The name topaz is from the Greek word to·paʹzi·on, which alludes to the Topaz Island situated in the Red Sea where the Greeks obtained the topazes familiar to Pliny the Elder and to other early writers. The book of Job links topaz with Cush, a region that bordered the Red Sea.

A topaz was among the precious stones on “the breastpiece of judgment” worn by High Priest Aaron. It was set as the middle stone in the first row of gems, and engraved upon it was the name of one of Israel’s 12 tribes. (Ex 28:2, 15, 17, 21; 39:10) The foundations of “the holy city, New Jerusalem, coming down out of heaven from God . . . were adorned with every sort of precious stone,” the ninth foundation being topaz.​—Re 21:2, 19, 20.