This page will contain discussion groups 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

This page about Topaz includes information from a Wikipedia article.
Additional articles about Topaz
News stories about Topaz
External links for Topaz
Videos for Topaz
Wikis about Topaz
Discussion Groups about Topaz
Blogs about Topaz
Images of Topaz

Topaz is also the birthstone of November. New Unimogs can be purchased on all major continents, however North American models are officially limited to the UGN series sold through Freightliner dealerships. 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. All other Unimog models are driven by a diesel powerplant varying from 80 horsepower to upwards of 280 horsepower (205 kW). 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. One of the more popular Unimog models with the largest single design production run is the Unimog 404, produced in troop carrier and radio box variants and powered by a 2 liter waterproofed Mercedes-Benz petrol engine that produced as much as 80 horsepower (60 kW) in the most common versions of this model. 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. They are also used extensively by the South African National Defence Force and the New Zealand Army.

It can be found in the Ural and Ilmen mountains, Czech Republic, Saxony, Norway, Sweden, Japan, Brazil, Mexico, and the United States. Unimogs have been used by many different militaries, including the German and Swiss armies. Topaz is found associated with the more acid rocks of the granite and rhyolite type and may be found with fluorite and cassiterite. Unimogs also feature a flexible frame that allows the tires a wide range of vertical movement to allow the truck to comfortably drive over extremely uneven terrain, even meter-high boulders. 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. They feature very high ground clearance — greater than the Humvee — made possible by portal gears that allow the axles and transmission to be higher than the tires' centers. It can also be irradiated, turning the stone a light and distinctive shade of blue. The Unimog (from the German "UNIversal-MOtor-Gerät", meaning "universal motor machine/equipment") is a series of trucks from Daimler-Benz designed shortly after WWII, originally to be used as slow-moving tractors for Germany's turnip harvest.

When heated, yellow topaz often becomes reddish-pink. reverse: 14.569/10.101/6.660/4.900/3.330/2.309/1.522/1.120. They may also be white, gray, green, blue, or reddish-yellow and transparent or translucent. forward: 9.570/6.635/4.375/3.219/2.188/1.517/1.000/0.736. Pure topaz is transparent but is usually tinted by impurities; typical topaz is wine or straw-yellow. transmission gearing

    . Topaz has a hardness of 8, a specific gravity of 3.4-3.6, and a vitreous lustre. Electronic Speed governor.

    The fracture is conchoidal to uneven. engine: 4.8 litre straight 4 Turbocharged OM924LA 218 HP (160 kW)

      . 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. average fuel consumption (diesel): not published. It crystallizes in the orthorhombic system and its crystals are mostly prismatic terminated by pyramidal and other faces, the basal pinacoid often being present. descent: not published. The mineral topaz is a silicate of aluminium and fluorine with the chemical formula Al2SiO4(F,OH)2. climb: not published.

      This article is about the mineral or gemstone, for other uses see: Topaz (disambiguation).. departure: 53 degrees. Mineral galleries. approach: 44 degrees. Mindat with location data. on a side slope: not published. Webmineral. traverse angle: not published

        .

        1200 mm (optional equipment). fording 800 mm (standard)

          . ground clearance: 476 mm (varies with tyre). fuel: 145 litres.

          tires: 365/85 R 20.5. gross weight: 11,800 kg. empty weight: 4,300 kg. turning radius: 14.5 m.

          wheelbase: 2336 mm. height: 2740 mm. length: 5410 mm. track width: 1920 mm.

          width: 2474 mm. discontinued: In Production. introduced: 2002. reverse: 20.12/11.09.

          forward: 14.93/8.23/4.47/2.46/1.52/1.0. transmission gearing

            . 2 Barrel Zenith NDIX-32 Carbeurator. Shielded Distributor Ignition, 24 Volt Electrical System.

            engine: 2.2 litre straight 6 SOHC (Mercedes Benz M180) 80 HP (60 kW)

              . average fuel consumption (gasoline): 10–14 mpg (US) (24–17 L/100 km). descent: 90% grade. climb: 70% grade.

              departure: 46 degrees. approach: 45 degrees. on a side slope: 42 degrees. traverse angle

                .

                fording (w/o equipment): 800 mm (31.5 in). ground clearance: 400 mm (15.7 in). fuel: 2 x 60 litre (15.9 US gal). tires: 10.5 x 20 (DOT).

                gross weight: 4400 kg (9700 lb). empty weight: 2900 kg (6390 lb). turning radius: 13 m (42.6 ft). wheelbase: 2900 mm (114 in).

                cargo bed: 3000 by 2000 mm (118 by 78 in), 2130 by 2080 mm (84 by 82 in) with double-cab. height: 2190 mm (86 in), cab height: 1600 mm (63 in). length: 4900 mm. width: 2130 mm (84 in).

                discontinued: 1980. introduced: 1955.

10-23-14 FTPPro Support FTPPro looks and feels just like Windows Explorer Contact FTPPro FTPPro Help Topics FTPPro Terms Of Use ftppro.com/1stzip.php ftppro.com/zip ftppro.com/browse2000.php PAD File Directory Business Search Directory Real Estate Database FunWebsites.org PressArchive.net WebExposure.us Display all your websites in one place HereIam.tv Celebrity Homepages Charity Directory Google+ Directory Move your favorite Unsigned Artist to the Top of the List