mineral

Blue Chalcedony

Silicon Dioxide (SiO2)

Hardness: 6.5-7 (Mohs scale), Color: Sky blue to lavender blue, Luster: Vitreous to waxy, Crystal Structure: Hexagonal (trigonal) - cryptocrystalline, Cleavage: None, Specific Gravity: 2.58–2.64

Hardness: 6

Identified May 10, 2026More mineral →

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Physical properties

Hardness: 6.5-7 (Mohs scale), Color: Sky blue to lavender blue, Luster: Vitreous to waxy, Crystal Structure: Hexagonal (trigonal) - cryptocrystalline, Cleavage: None, Specific Gravity: 2.58–2.64

Formation & geological history

Formed from the deposition of silica from water in cavities or veins within igneous or sedimentary rocks. It often forms at low temperatures in volcanic environments.

Uses & applications

Primarily used in jewelry as cabochons, beads, and carvings. Also used for ornamental objects and as a healing stone in holistic practices.

Geological facts

Blue chalcedony is a cryptocrystalline variety of quartz. Famous varieties include 'Mohave Blue' and 'African Blue'. It has been used for seals and amulets since ancient times in the Mediterranean region.

Field identification & locations

Identify by its waxy luster, lack of cleavage, and translucent blue color. Commonly found in Namibia, Turkey, India, and the United States (California/Oregon). It is often found as nodules or vein fillings.