Turquoise

Physical Properties

Hardness: 5-6 (Mohs scale), Color: Sky blue to blue-green, Luster: Waxy to subvitreous, Crystal structure: Triclinic (usually cryptocrystalline or massive), Cleavage: Perfect (rarely seen in massive forms), Specific gravity: 2.6-2.9

Formation & Geological History

Formed through the infiltration of moisture through rocks containing minerals like copper, aluminum, and phosphorus. It is a secondary mineral usually found in volcanic rocks, particularly in weathered aridisol environments. Common geological ages vary, but many deposits are linked to Tertiary or younger tectonic activity.

Uses & Applications

Predominantly used as a gemstone for jewelry, carvings, and ornamental inlay. It has been used for thousands of years by civilizations like the Egyptians and Native Americans.

Geological Facts

Turquoise is one of the oldest known gemstones. The name comes from the French expression 'pierre turquoise', meaning 'Turkish stone', as it was originally brought to Europe through Turkey from mines in Iran (Persia).

Field Identification & Locations

Identify by its unique robin's-egg blue or green color and waxy luster. In the field, look for thin veins or nodules in weathered volcanic host rocks. Common locations include the Southwestern USA (Arizona, Nevada), Iran, China, and Egypt.

Identified on: 4/17/2026

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