The Hebrew word is pitdah, and has been supposed to be derived from an island in the Red Sea called Topazos. This would account for the ancient versions calling it 'topaz,' but the gem is supposed to agree with our chrysolite. Job 28:19 speaks of 'the topaz of Ethiopia.' It was one of the jewels in the breastplate, Exodus 28:17; Exodus 39:10; and is included in the prophetical description of the symbolical 'king of Tyrus.' Ezekiel 28:13 . In the N.T. τοπάζιον points to the same stone. Revelation 21:20 . It is a silicate of magnesia and iron, and being comparatively soft has to be worn with care.