gemstone

Turquoise

CuAl6(PO4)4(OH)8·4H2O

Hardness: 5-6, Color: Light blue to green, Luster: Waxy to subvitreous, Crystal structure: Triclinic, Cleavage: Good, Specific gravity: 2.6-2.9. It is characterized by its typical blue-green coloration and often features a prominent, dark matrix webbing.

Identified July 26, 2026More gemstone →

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Physical properties

Formation & geological history

Turquoise forms through the weathering and oxidation of pre-existing minerals in a secondary process. It is typically found in arid regions, forming in the cavities and veins of weathered aluminum-rich, volcanic, and sedimentary rocks, often associated with copper deposits.

Uses & applications

Widely used for ornamental and jewelry purposes due to its distinctive color and striking matrix patterns. Often cut into cabochons, carved, or inlaid.

Geological facts

Prized by many ancient cultures, including Ancient Egypt, Persia, and Native American societies, who considered it a holy stone and a bringer of good fortune. It has historically been used in everything from royal ornaments to religious artifacts.

Field identification & locations

Identified by its distinctive color and typical matrix. The specific patterns and hues often indicate the exact mine of origin (e.g., Sleeping Beauty, Kingman, or Royston). Collectors value untreated, natural stones with striking color and well-defined spiderweb matrices.