Topaz (from Greek:Τοπάζιος, the ancient name of St. John's Island in the Red Sea) is a silicate mineral of aluminium and fluorine.
Many modern English translations of the Bible mention topaz in Exodus 28:17 in the King James version, in reference to stone in the Hoshen: "And thou shalt set in it settings of stones, even four rows of stones: the first row shall be a sardius, a topaz, and a carbuncle (garnet): this shall be the first row." However, the translations derive from a type that define topaz as a yellow stone that was not topaz but probably chrysolite.
Pure topaz is colourless and transparent but is usually tinted by impurities; typical topaz is yellow, pale gray, reddish-orange, or blue brown. It can also be made white, pale green, blue, gold, pink (rare), reddish-yellow or opaque to transparent/translucent.
Topaz has been around for a while; the Greeks believed it had power to increase strength and to make its wearer invisible while the Romans believed it had power to improve eyesight. The Egyptians wore it as an amulet to protect them from injury. During the Middle Ages topaz was thought to both heal physical and mental disorders and prevent death. The most famous topaz is a colourless topaz that was originally thought to be a diamond. It is a 1680 carat stone known as the "Braganza Diamond" set in the Portuguese Crown Jewels.