mineral

Turquoise, Pearl, and Coral Necklace

CuAl6(PO4)4(OH)8·4H2O (Turquoise) / CaCO3 (Pearl and Coral)

Turquoise: Hardness 5-6, sky-blue color, waxy to sub-vitreous luster, triclinic. Pearls: Hardness 2.5-4.5, white with orient luster. Coral: Hardness 3-4, vivid red.

Identified May 9, 2026More mineral →

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Physical properties

Turquoise: Hardness 5-6, sky-blue color, waxy to sub-vitreous luster, triclinic. Pearls: Hardness 2.5-4.5, white with orient luster. Coral: Hardness 3-4, vivid red.

Formation & geological history

Turquoise forms via secondary mineralization in arid regions. Pearls are organic gems formed within mollusks. Red coral consists of calcium carbonate skeletons from marine polyps.

Uses & applications

Primary use in jewelry, fashion accessories, and as collectible semi-precious gemstones.

Geological facts

Turquoise has been mined since at least 6000 BCE in Egypt. Red coral (Corallium rubrum) is often called 'precious coral' and is heavily regulated in many regions.

Field identification & locations

Identification includes checking for 'matrix' patterns in turquoise and the 'tooth test' for pearls. Found in jewelry markets and vintage collections.

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