gemstone

Red Coral (Precious Coral)

Corallium rubrum (Calcium Carbonate, CaCO3)

Hardness: 3.5 on Mohs scale. Color: Intense deep red to pink-red. Luster: Vitreous to dull in raw state, polished to high waxy/vitreous luster. Structure: Microcrystalline aragonite/calcite framework.

Hardness: 3
Color: Intense deep red to pink-red

Identified July 28, 2026More gemstone →

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Physical properties

Formation & geological history

Biogenic origin formed from the calcareous skeletons of marine polyp colonies living in warm, sub-tropical to tropical ocean waters (primarily Mediterranean Sea, Western Pacific, Japan, and Taiwan).

Uses & applications

Extensively used in jewelry making including beaded bracelets, necklaces, cabochons, and ornamental carvings. Also holds cultural and astrological significance.

Geological facts

Precious coral is an organic gemstone created by marine invertebrates. It has been harvested since antiquity, with red coral trade documented over 5,000 years ago in ancient Mediterranean civilizations.

Field identification & locations

Identify by its characteristic fine parallel striations along the length of raw branches, effervescent reaction to dilute acid (calcium carbonate), and warm feel compared to cold glass imitations.

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