|Dimensions (mm)||7 x 5 x 3mm|
|Weight (carats)||3.5 carats|
New Faceted Blue 3.5 ct Topaz gemstone pendant with 14K GOLD list price $398.00
Topaz is a rare silicate with a chemical composition
It usually forms in fractures and cavities
late in their cooling history.
It is also found as water-worn pebbles in stream sediments derived from those igneous rocks.
Topaz is a well-known gemstone sold in a wide variety of attractive colors.
Some of these colors are natural, while others are produced by treating pale
or colorless topaz with heat, radiation, or metallic coatings.
Physical Properties of Topaz
|Color||Natural colors include: colorless, yellow, orange, red, pink, blue, green. Occurs in a wide range of treated colors, most often blue.|
|Streak||Colorless - harder than the streak plate.|
|Diaphaneity||Translucent to transparent.|
|Cleavage||Perfect basal cleavage.|
|Specific Gravity||3.4 to 3.6|
|Diagnostic Properties||Hardness, prismatic crystals, sometimes striated, cleavage, specific gravity.|
|Uses||Gemstone, Mohs hardness index mineral.|
One of the best-known physical properties of topaz is its hardness. It has a hardness of 8 It also serves as the Mohs hardness scale index mineral for a hardness of 8. Every student who takes an introductory geology course learns about the hardness of topaz.
Most topaz is colorless or milky. Yellowish and brownish colors are also common. Natural pink, orange, red, purple, and blue topaz are rare and valuable if they are of gem quality.
When allowed to grow unrestricted, topaz forms orthorhombic crystals, often with striations that parallel the long axis of the crystal. It also has a distinct basal cleavage that breaks perpendicular to the long axis of the crystal. This cleavage makes topaz a more fragile gemstone than its hardness of 8 would imply. Hardness is the resistance to being scratched, but the ability to resist breakage is a property known as tenacity.
Topaz has a specific gravity that ranges between 3.4 and 3.6. This is quite high for a mineral composed of aluminum, silicon, and gaseous elements.
|Starts||25th Apr 2017 12:34pm PDT|
|Standard Shipping||$0.00||21 Days|
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