Infobox mineral
name = Topaz
category = Silicate mineral
boxwidth =
boxbgcolor =

imagesize = 170px
caption = a group of topaz crystals on matrix
formula = Al2SiO4(F,OH)2
color = Clear (if no impurities), blue, brown, orange, gray, yellow, green, pink and reddish pink.
system = orthorhombic
fracture = conchoidal
mohs = 8
luster = Vitreous/glossy
gravity = 3.4–3.6

Topaz is a silicate mineral of aluminium and fluorine with the chemical formula Al2SiO4(F,OH)2. It is the birthstone of the month November. It crystallizes in the orthorhombic group and its crystals are mostly prismatic terminated by pyramidal and other faces, the basal pinacoid often being present. It has an easy and perfect basal cleavage, meaning that gemstones or other fine specimens have to be handled with care to avoid developing cleavage flaws. The fracture is conchoidal to uneven. Topaz has a hardness of 8, a specific gravity of 3.4–3.6, and a vitreous luster. Pure topaz is transparent but is usually tinted by impurities; typical topaz is wine or straw-yellow. They may be made white, gray, green, blue, pink or reddish-yellow and transparent or translucent.

Localities and occurrence

Topaz is commonly associated with silicic igneous rocks of the granite and rhyolite type. It typically crystallizes in granitic pegmatites or in vapor cavities in rhyolite lava flows like those at Topaz Mountain in western Utah. It may be found with fluorite and cassiterite. It can be found in the Ural and Ilmen mountains, Afghanistan, Sri Lanka, Czech Republic, Germany, Norway, Pakistan, Italy, Sweden, Japan, Brazil, Mexico, Flinders Island and the United States.Some clear topaz crystals from Brazilian pegmatites can reach boulder size and weigh hundreds of pounds. Crystals of this size may be seen in museum collections. The famous Braganza diamond is in most likelihood a topaz. The Topaz of Aurungzebe, observed by Jean Baptiste Tavernier measured 157.75 carats. [ [ Famous and Notheworthy Topazes] Rao Bahadur, A Handbook of Precious Stones, Geological Survey of India]

Etymology and historical and mythical usage

The name "topaz" is derived from the Greek "Τοπάζιος" (Τοpáziοs), which was the ancient name of St. John's Island in the Red Sea which was difficult to find and from which a yellow stone (now believed to be chrysolite: yellowish olivine) was mined in ancient times; topaz itself (rather than "topazios") wasn't really known about before the classical era. [ Nicols who wrote one of the first systematic treatises on minerals and gemstones dedicated two chapters on the topic in 1652: A Lapidary or History of Gemstones, University of Cambridge, 1652 ] In the Middle Ages the name topaz was used to refer to any yellow gemstone, but now the name is only properly applied to the silicate described above.

Many modern English translations of the Bible, including the King James Version mention "topaz" in Exodus 28:17 in reference to a 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: this shall be the first row." However, since these translations as "topaz" all derive from the Septuagint translation "topazi [os] ", which as mentioned above referred to a yellow stone that wasn't topaz, probably chrysolite, it should be borne in mind that topaz is not meant here. [ see for extensive discussion Oliver Farrington, Gems and Gem Minerals, Chicago, 1903. Farrington was curator of Natural History Museum in Chicago. ] The masoretic text (the Hebrew on which most modern protestant bible translations of the Old Testament are based) has "pitdah" as the gem the stone is made from; "pitdah" is of unknown meaning, though scholars think it is related to an Assyrian word meaning "flashed". There is a wide range of views among traditional sources about which tribe of the Israelites the stone refers to.

Yellow topaz is the traditional November birthstone, the symbol of friendship, and the state gemstone for the US State of Utah.

Blue topaz is the Texas state gemstone, often cut with the Lone Star cut - the Texas state gemstone cut showing a star in the heart of the gem. [ [ Texas State Library & Archives Commission Web site] ]

= References =
* Hurlbut, Cornelius S.; Klein, Cornelis, 1985, "Manual of Mineralogy", 20th ed., ISBN 0-471-80580-7

External links

* [ Pink Topaz, Biblical Topaz References] a few dozen full text historical references on Topaz
* [ Webmineral]
* [ Mindat with location data]
* [ Mineral galleries]

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Topaz — Herkunft Tschechien, Prag 1984 Art Malus domestica Kreuzung aus Rubin x Vanda, 1984 Liste der Apfelsorten Topaz ist eine noch relativ neue Apfelsort …   Deutsch Wikipedia

  • topaz — TOPÁZ, topaze, s.n. Silicat natural de aluminiu cu fluor, cristalizat în sistemul rombic, de obicei de culoare galbenă, folosită ca piatră preţioasă. [pl. şi: topazuri] – Din fr. topaze. Trimis de romac, 13.07.2008. Sursa: DEX 98  TOPÁZ s.… …   Dicționar Român

  • Topaz — To paz, n. [OE. topas, F. topaze, L. topazos, or topazion, a kind of precious stone, Gr. to pazos, topa zion; possibly akin to Skr. tap to glow (cf. {Tepid}). According to some, the name is from Topazos, a small island in the Red Sea, where the… …   The Collaborative International Dictionary of English

  • Topaz — f English: one of the rarer examples of the class of modern female names taken from vocabulary words denoting gemstones. The topaz gets its name via French and Latin from Greek; it is probably ultimately of oriental origin. In the Middle Ages… …   First names dictionary

  • topaz — [tō′paz΄] n. [ME topace < OFr topase < L topazus < Gr topazos] 1. a light colored or colorless, very hard, orthorhombic mineral, Al2 (SiO4)(F,OH) 2, often used as a gem; hydrous aluminum silicate: see MOHS SCALE 2. any of a various… …   English World dictionary

  • tòpaz — m min. aluminijev fluorid silikat, najčešće žute boje, cijenjen kao dragulj ✧ {{001f}}grč …   Veliki rječnik hrvatskoga jezika

  • topaz — (n.) colored crystalline gem, late 13c., from O.Fr. topace (11c.), from L. topazus, from Gk. topazos, topazion, of obscure origin. Pliny says it was named for a remote island in the Red or Arabian Sea, where it was mined, but this might be folk… …   Etymology dictionary

  • topaz — s. m. 1. Cristão mestiço, no Oriente. 2.  [Antigo] Intérprete chinês …   Dicionário da Língua Portuguesa

  • topaz — tòpaz m DEFINICIJA min. aluminijev fluorid silikat, najčešće žute boje, cijenjen kao dragulj ETIMOLOGIJA grč. tópazos …   Hrvatski jezični portal

  • topaz — {{/stl 13}}{{stl 8}}rz. mnż I, D. u, Mc. topazzie {{/stl 8}}{{stl 7}} przezroczysty minerał o pięknym zabarwieniu w różnych odcieniach, stosowany jako kamień ozdobny w jubilerstwie : {{/stl 7}}{{stl 10}}Naszyjnik z topazami. <łac.> {{/stl… …   Langenscheidt Polski wyjaśnień

  • topaz — ► NOUN 1) a colourless, yellow, or pale blue precious stone. 2) a dark yellow colour. ORIGIN Greek topazos …   English terms dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.