Little Gems
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Scapolite
Sunstone
Specials
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Opal.
 |
Oregon Opal Luminescent
yellow opal.
Mexican Cherry Opal Luminous red to orange opal. |
Colour: Colourless, yellow, orange, red
Moh’s Hardness: 5-6.5
Refractive Index: 1.44-1.46
Critical Angle: 43.98°
Specific Gravity: 1.9-2.23
Fracture: Conchoidal, brittle, splinters with ease.
Cleavage: None
Dispersion: None
Heat Sensitivity: Moderate to high (err on the side of high sensitivity).
Birefringence (double refraction): None
Crystal Structure: Amorphous