This page will contain wikis about Topaz, as they become available.

Topaz

This article is about the mineral or gemstone, for other uses see: Topaz (disambiguation).

Topaz 4 Carat Oval Shape Topaz Gemstone Ring Enhanced with Azotic(r)Treatment Heart Cut Sky Blue Topaz Ring

The mineral topaz is a silicate of aluminium and fluorine with the chemical formula Al2SiO4(F,OH)2. It crystallizes in the orthorhombic system 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 and so gemstones or other fine specimens should 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 lustre. Pure topaz is transparent but is usually tinted by impurities; typical topaz is wine or straw-yellow. They may also be white, gray, green, blue, or reddish-yellow and transparent or translucent. When heated, yellow topaz often becomes reddish-pink. It can also be irradiated, turning the stone a light and distinctive shade of blue. A recent trend in jewelry is the manufacture of topaz specimens that display iridescent colors, by applying a thin layer of titanium oxide via physical vapor deposition.

Topaz is found associated with the more acid rocks of the granite and rhyolite type and may be found with fluorite and cassiterite. It can be found in the Ural and Ilmen mountains, Czech Republic, Saxony, Norway, Sweden, Japan, Brazil, Mexico, and the United States.

Etymology and historical/mythical usage

The name "topaz" is derived from the Greek topazos, "to seek," which was the name of an island in the Red Sea that was difficult to find and from which a yellow stone (now believed to be a yellowish olivine) was mined in ancient times. 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.

According to Rebbenu Bachya, the word "Leshem" in the verse Exodus 28:19 means "Topaz" and was the stone on the Ephod representing the tribe of Dan.

Topaz is also the birthstone of November.

Example of Heat Treated Topaz-Pink Topaz Pear Cut Ring

References

  • Webmineral
  • Mindat with location data
  • Mineral galleries

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Topaz is also the birthstone of November.
. According to Rebbenu Bachya, the word "Leshem" in the verse Exodus 28:19 means "Topaz" and was the stone on the Ephod representing the tribe of Dan. At the very worst, the area may even have to be amputated. 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. However, because of the notable tissue damage caused by the venom, even with good treatment the bite is sure to leave a permanent mark. The name "topaz" is derived from the Greek topazos, "to seek," which was the name of an island in the Red Sea that was difficult to find and from which a yellow stone (now believed to be a yellowish olivine) was mined in ancient times. The exact effect strongly depends on the type of viper and the constitution and build of the human in question.

It can be found in the Ural and Ilmen mountains, Czech Republic, Saxony, Norway, Sweden, Japan, Brazil, Mexico, and the United States. Thus, a bite to humans can, at the worst, be even fatal. Topaz is found associated with the more acid rocks of the granite and rhyolite type and may be found with fluorite and cassiterite. Since vipers possess a poor digestive system, they rely on the venom to do the job via rapid tissue damage. A recent trend in jewelry is the manufacture of topaz specimens that display iridescent colors, by applying a thin layer of titanium oxide via physical vapor deposition. The viper's venom is a haemotoxin, and is generally more dangerous than the neurotoxin of a cobra. It can also be irradiated, turning the stone a light and distinctive shade of blue. Being 0.3–3 m long, vipers feed on small animals, which are injected with venom and then followed until they die.

When heated, yellow topaz often becomes reddish-pink. Their eyes have irises like those of a cat. They may also be white, gray, green, blue, or reddish-yellow and transparent or translucent. The broad areas of the head house the venom glands. Pure topaz is transparent but is usually tinted by impurities; typical topaz is wine or straw-yellow. They also have triangle-shaped heads with a distinctly narrower neck. Topaz has a hardness of 8, a specific gravity of 3.4-3.6, and a vitreous lustre. They are characterised by long erectile fangs, which are folded back when not in use.

The fracture is conchoidal to uneven. Vipers are venomous snakes belonging to the Viperidae family (consisting of roughly 150 species). It has an easy and perfect basal cleavage and so gemstones or other fine specimens should be handled with care to avoid developing cleavage flaws. ISBN 080696460X. It crystallizes in the orthorhombic system and its crystals are mostly prismatic terminated by pyramidal and other faces, the basal pinacoid often being present. New York: Sterling Publishing, 1987. The mineral topaz is a silicate of aluminium and fluorine with the chemical formula Al2SiO4(F,OH)2. Living Snakes of the World in Color.

This article is about the mineral or gemstone, for other uses see: Topaz (disambiguation).. Mehrtens, John M. Mineral galleries. Pit Vipers may be treated as a subfamily (Crotalinae) of the viper family Viperidae (with "true vipers" or pitless vipers in the subfamily Viperinae), or as a family of their own, Crotalidae. Mindat with location data. Adder. Webmineral.

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