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Gemstone Crystal System Density Hardness Refractive index Treatments
organic 2.65 3.5-4.0 1.486-1.658 dying



coral rough and cut

Most Valuable=Red.
Orange, pink, peach, black, brown, metallic gold

Clarity: Semi-translucent to opaque
Optic Character:
Cause of Color: Organic Matter (carotenoid)
Fluorescence: Generally Inert
Fracture : Splintery to uneven
Luster : Dull
Cleavage :
Durability: Fair

Characteristics for Identification:
Liquid and phase inclusions, Tubular inclusions

Mediteranean Sea, Pacific Ocean, South Seas

coral reef

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Coral is one of the few organic gems. It is the exoskeleton of colonial polyps. These are small animals that create their branching homes from calcium carbonate dissolved in sea water. The colors of gem coral range from a pale pink (angel-skin) to oranges and reds. Coral has been used throughout our history; it was pictured on a Summerian vase dated at 3000 BC It was traded between the Mediterranean and India at the time of the birth of Christ. Coral was introduced into Mesoamerica by the Spaniards. Native Americans used it extensively in jewelry. Coral was used in Roman times to protect children from danger. It is still worn in Italy today to protect from the evil eye.

Varieties of Coral:

Red Coral
Pink Angel Skin Coral
White Coral
Black Coral

This gemstone is often confused with:
Red Jasper
White or Black Jade
Black Onyx