Natural Untreated Loose Gemstones

Topaz Pleochroic Bicolor Cabochon Natural Untreated Gemstone Ukraine 177.54 ct

Topaz Pleochroic Bicolor Cabochon Natural Untreated Gemstone Ukraine 177.54 ct
Topaz Pleochroic Bicolor Cabochon Natural Untreated Gemstone Ukraine 177.54 ct
Topaz Pleochroic Bicolor Cabochon Natural Untreated Gemstone Ukraine 177.54 ct
Topaz Pleochroic Bicolor Cabochon Natural Untreated Gemstone Ukraine 177.54 ct
Topaz Pleochroic Bicolor Cabochon Natural Untreated Gemstone Ukraine 177.54 ct
Topaz Pleochroic Bicolor Cabochon Natural Untreated Gemstone Ukraine 177.54 ct
Topaz Pleochroic Bicolor Cabochon Natural Untreated Gemstone Ukraine 177.54 ct
Topaz Pleochroic Bicolor Cabochon Natural Untreated Gemstone Ukraine 177.54 ct

Topaz Pleochroic Bicolor Cabochon Natural Untreated Gemstone Ukraine 177.54 ct    Topaz Pleochroic Bicolor Cabochon Natural Untreated Gemstone Ukraine 177.54 ct

Natural untreated bi color Topaz cabochon. Mineral inclusions have been formed by post-magmatic, fluid-induced processes, extended from pegmatite to hydrothermal stages of magma crystallization. Photos are taken in daylight lamps and colors can vary slightly from original - much more transparent and translucent in real life.

Weight : 177.54 carat Size : 32.1 x 27 x 18.3 mm. Named after Topasos Island in the Red Sea. In antique times, the name was probably used for the gemstone that is now known as Peridot. Occurs in pegmatites and high-temperature quartz veins, also in cavities in granites and rhyolites.

An old and famous pegmatite district excellent'heliodor' beryls and topaz, from huge pockets (chamber pegmatites). A group of topaz crystals. A = 4.65 Å. B = 8.8 Å, c = 8.4 Å; Z = 4. Colorless (if no impurities), blue, brown, orange, gray, yellow, green, pink and reddish pink. Prismatic crystals with faces striated parallel to long dimension; also columnar, compact, massive. Orthorhombic - dipyramidal H-M symbol. (2/m 2/m 2/m) Space group. = 1.6061.629 n. = 1.6091.631 n. Weak in thick sections X = yellow; Y = yellow, violet, reddish; Z = violet, bluish, yellow, pink. Short UV=golden yellow; Long UV=cream. Topaz is a silicate mineral. Topaz crystallizes in the orthorhombic. Are mostly prismatic terminated by pyramidal and other faces. Facet cut topaz gemstones in various colors. Yellow topaz in stepped kite-shaped cut. Pure topaz is colorless and transparent but is usually tinted by impurities; typical topaz is wine red, yellow, pale gray, reddish-orange, or blue brown. It can also be white, pale green, blue, gold, pink (rare), reddish-yellow or opaque to transparent/translucent. Orange topaz, also known as precious topaz, is the traditional November birthstone. The symbol of friendship, and the state gemstone. Of the US state of Utah. Imperial topaz is yellow, pink (rare, if natural) or pink-orange. Brazilian Imperial Topaz can often have a bright yellow to deep golden brown hue, sometimes even violet.

Many brown or pale topazes are treated to make them bright yellow, gold, pink or violet colored. Some imperial topaz stones can fade on exposure to sunlight for an extended period of time. Blue topaz is the state gemstone of the US state of Texas. Naturally occurring blue topaz is quite rare.

Typically, colorless, gray or pale yellow and blue material is heat treated and irradiated. To produce a more desired darker blue. Mystic topaz is colorless topaz which has been artificially coated giving it the desired rainbow effect. Topaz is commonly associated with silicic.

Igneous rocks of the granite. It typically crystallizes in granitic pegmatites. Or in vapor cavities in rhyolite lava flows including those at Topaz Mountain in western Utah and Chivinar. It can be found with fluorite.

In various areas including the Ural. And Ilmen mountains of Russia.

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. Observed by Jean Baptiste Tavernier.

A more recent gem, weighed a massive 22,892.5 carats. Colorless and light-blue varieties of topaz are found in Precambrian.

Granite in Mason County, Texas. There is no commercial mining of topaz in that area. Imperial Topaz from Ouro Preto, Minas Gerais, Brazil. The name "topaz" is usually derived via Old French.

From , the ancient name of St. Which was difficult to find and from which a yellow stone now believed to be chrysolite. Was mined in ancient times; topaz itself (rather than topazios) was not really known before the classical era.

Is a legendary island in the Red Sea. And the mineral "topaz" was first mined there.

Alternatively, the word topaz may be related to the Sanskrit word "tapas", meaning "heat" or "fire". Nicols, the author of one of the first systematic treatises on minerals and gemstones, dedicated two chapters to the topic in 1652. The name topaz was used to refer to any yellow gemstone, but in modern times it denotes only the silicate described above.

Many modern English translations of the Bible. Including the King James Version. However, because these translations as topaz all derive from the Septuagint.

Translation topazi[os] , which as mentioned above referred to a yellow stone that was not topaz, but probably chrysolite chrysoberyl. , it should be borne in mind that topaz is likely not meant here.

On which most modern Protestant. Bible translations of the Old Testament. Are based has pitdah as the gem the stone is made from; some scholars think it is related to an Assyrian.

More likely, "pitdah" is derived from Sanskrit. Dah = burn, meaning "yellow burn" or, metaphorically, "fiery". Klein, Cornelis, 1985, Manual of Mineralogy , 20th ed. Chantilly, VA, US: Mineralogical Society of America. Natural History Museum of Los Angeles County. State Gem Texas Blue Topaz.

State Gemstone Cut Lone Star Cut. Rao Bahadur, A Handbook of Precious Stones, Geological Survey of India. Handbook of Texas Online Mineral Resources and Mining. Mason, Texas Chamber of Commerce Web site.

A Lapidary or History of Gemstones , University of Cambridge, 1652. See for extensive discussion Oliver Farrington, Gems and Gem Minerals. Farrington was curator of Natural History Museum in Chicago. Wikimedia Commons has media related to Topaz. Topaz and other minerals found at Topaz Mountain, Juab County.

The item "Topaz Pleochroic Bicolor Cabochon Natural Untreated Gemstone Ukraine 177.54 ct" is in sale since Friday, July 22, 2016. This item is in the category "Jewelry & Watches\Loose Diamonds & Gemstones\Loose Gemstones\Topaz".

The seller is "classicrocksandgems2" and is located in Morsbach. This item can be shipped worldwide.

  • Variety/Type: Natural untreated topaz cabochon
  • Shape: Cushion
  • Brand: Classic Rocks and Gems
  • Total Carat Weight (TCW): 177.54 ct
  • Treatment: None (No Enhancement)
  • Transparency: Transparent with inclusions
  • Cut Grade: Very Good
  • Country of Origin: Ukraine


Topaz Pleochroic Bicolor Cabochon Natural Untreated Gemstone Ukraine 177.54 ct    Topaz Pleochroic Bicolor Cabochon Natural Untreated Gemstone Ukraine 177.54 ct