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Glittering
Stones >> Semi
Precious Stones >> Topaz
Semi Precious Stone Topaz
Topaz is very common gemstone that has been
used few centuries in jewelry. Its golden brown
to yellow color is classic but it is confused with the less valuable
citrine that is sold under the name topaz. The
blue topaz that is often confused with aquamarine
is not often natural and is produced by irradiating and then heating
clear crystals. Topaz is the November Birthstone.
The mineral topaz is a silicate of aluminum and also fluorine
with the chemical formula (AlF) 2SiO4. It is orthorhombic and
its crystals are mainly prismatic terminated
by pyramidal and other faces also, the basal pinacoid often being
present. It has an easy and perfect basal cleavage and hence gemstones
and other fine specimens must be handled with care to
avoid developing cleavage flaws. The fracture is concordat to
uneven. Topaz has a hardness of 7, a specific gravity of 3.4-3.5,
and a vitreous luster. Pure topaz is transparent but it is usually
tinted by impurities; typical topaz is wine and straw-yellow.
They can also be white, gray, green, blue, or reddish-yellow also
and transparent or translucent. When heated, yellow topaz
often becomes reddish-pink.
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Historical Facts of Topaz
| Refractive Index |
1.629 - 1.637 |
| Chemical Composition |
AL(F,OH)2SIO4 |
| Hardness |
8 |
| Crystal Group |
Orthorhombic |
| Density |
3.52 - 3.56 |
| Color |
Colorless, Blue, Yellow brown, Pinkish orange, Red orange,
Red brown, Tan, White, Gray, Green, Pink, Reddish yellow.
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| Ocurrence |
Brazil, Sri Lanka, Nigeria, Germany, Australia, Japan,
Russia, Ireland, Zimbabwe, Western Utah, United States |
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Gemstone Jewelry Topaz
| Topaz Bracelet |
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| Topaz Earrings |
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| Topaz Necklace |
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| Topaz Rings |
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