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| Turqoise and diamond crown in Smitsonian Institute |
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| Turquoise boulder from Smithsonian Institute |
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| Turquoise necklace |
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Turqoise:
Chemistry:
Hydrated Copper Aluminium Phosphate
Class: Phosphates
Uses: As an ormamental
stone for carving and Jewelry
Turquoise is possibly the most valuable , non-transparent mineral in
the jewelry trade. It has been mined for eons since at least 6000 B.C. by early Egyptions. Its history also includes beautiful
creations by Native Americans and Persians. Its popularity is increasing lately. The finest Turqoise comes from Iran but is
challenged by some southwestern United States specimens. The name comes from a french word which means 'stone of Turkey',
from where Persian specimens passed on the way to Europe.
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Colour is of course, turquoise but this varies from green through greenish blue
to sky blue shades.
Luster is dull to waxy, vitreous in macro-crystals.
Transparency specimens
are opaque.
Crystal System is triclinic:bar 1
Cleavage is perfect in two directions,
but is not often seen.
Fracture is conchoidal and smooth.
Hardness is 5-6
Specific
Gravity is2.6-2.8
Streak is white with a greenish tint
Associated minerals
are pyrite, limonite, quartz and clays
Other Characteristics Color can change with exposure to skin
oils
Notable Occurences include Arizona and New Mexico, USA, Australia, Iran, Afghanistan
and other localities in the middle East
Best Field Indicators are crystal habit, hardness, luster, color
and associations
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