a. A colorless, blue, yellow, brown, or pink aluminum silicate mineral, often found in association with granitic rocks and valued as a gemstone.
b. Any of various yellow gemstones, especially a yellow variety of sapphire or corundum.
2. A light yellow variety of quartz.
[Middle English topace, from Old French, from Latin topazus, a precious green stone, from Greek topazos, topazion, a precious green stone such as peridot or chrysolite, perhaps after Topazios, ancient name (said by Pliny the Elder to mean “to be sought” in the local Troglodyte language, since sailors would use it as a landmark) of Zabargad or St. John's Island, an island in the Red Sea off the coast of Egypt formed of rocks rich in peridot.]
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