mineral

Chrysocolla in Chalcedony (Gem Silica)

Hydrated copper phyllosilicate and silicon dioxide (SiO2 with (Cu,Al)2H2Si2O5(OH)4)

Hardness: 7 (for the quartz/chalcedony host) down to 2-4 (for chrysocolla inclusions); Color: Vibrant turquoise-blue to cyan with brownish matrix; Luster: Vitreous to waxy; Crystal structure: Trigonal (quartz) and monoclinic (chrysocolla); Specific gravity: 2.2 to 2.6

Color: Vibrant turquoise-blue to cyan with brownish matrix
Luster: Vitreous to waxy

Identified August 1, 2026More mineral →

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Physical properties

Formation & geological history

Formed in the oxidation zones of copper ore bodies, where silica-rich solutions interact with copper-bearing minerals, depositing chrysocolla within fractures and cavities of host chalcedony.

Uses & applications

Used primarily in lapidary arts, high-end jewelry, and as a prized collector's mineral specimen.

Geological facts

Gem silica is the rarest and most valuable form of chrysocolla, where chalcedony has completely or partially replaced the softer mineral, giving it a hardness suitable for gem-cutting.

Field identification & locations

Found in copper-rich mining regions globally, most notably Arizona (USA), Peru, and Mexico. Identified by its striking cyan-blue color within a chalcedony matrix and conchoidal fracture.

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