topaz

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A colorless, blue, yellow, brown, or pink aluminum silicate mineral, often found in association with granitic rocks and valued as a gemstone, especially in the brown and pink varieties.
2. n. Any of various yellow gemstones, especially a yellow variety of sapphire or corundum.
3. n. A light yellow variety of quartz.
4. n. Either of two South American hummingbirds (Topaza pyra or T. pella) having colorful plumage.

Century Dictionary and Cyclopedia

1. n. A mineral of a vitreous luster, transparent or translucent, sometimes colorless, often of a yellow, white, green, or pale-blue color. It is a silicate of aluminium in which the oxygen is partly replaced by fluorin. The fracture is subconchoidal and uneven; the hardness is somewhat greater than that of quartz. It usually occurs in prismatic crystals with perfect basal cleavage, also massive, sometimes columnar (the variety pycnite). Topaz occurs generally in granitic rocks, less often in cavities in volcanic rock as rhyolite. It is found in many parts of the world, as Cornwall, Scotland, Saxony, Siberia, Brazil, Mexico, and the United States. The finest varieties are obtained from the mountains of Brazil and the Ural Mountains, Those from Brazil have deep-yellow tints; those from Siberia have a bluish tinge; the Saxon topaz has a pale wine-yellow. The purest topazes from Brazil, when cut in facets, closely resemble the diamond in luster and brilliance.
2. n. In heraldry, the tincture or in blazoning by the precious stones. See blazon, n., 2.
3. n. A humming-bird, Topaza pella or T. pyra.

Wiktionary

1. n. a clear, yellowish-brown gemstone.
2. n. a yellowish-brown color, like that of the gemstone.
3. adj. Of a yellowish-brown color, like that of the gemstone.

GNU Webster's 1913

1. n. A mineral occurring in rhombic prisms, generally yellowish and pellucid, also colorless, and of greenesh, bluish, or brownish shades. It sometimes occurs massive and opaque. It is a fluosilicate of alumina, and is used as a gem.
2. n. Either one of two species of large, brilliantly colored humming birds of the genus Topaza (Topaza pella or Topaza pyra), of South America and the West Indies.

WordNet 3.0

1. n. a light brown the color of topaz
2. n. a mineral (fluosilicate of aluminum) that occurs in crystals of various colors and is used as a gemstone
3. n. a yellow quartz