mineral

Chrysocolla in Quartz (Gem Silica)

Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla) / SiO2 (Quartz)

Hardness: 7 (when silicified); Color: Blue-green, turquoise, cyan; Luster: Vitreous to waxy; Crystal structure: Amorphous to microcrystalline; Cleavage: None/Conchoidal fracture; Specific gravity: 2.0-2.4 (Chrysocolla) up to 2.65 (Quartz)

Hardness: 7 (when silicified)
Color: Blue-green, turquoise, cyan
Luster: Vitreous to waxy

Identified April 7, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed in the oxidation zones of copper ore bodies. Secondary copper-bearing fluids permeate host rocks (often quartz or chalcedony) at low temperatures, resulting in the mineralization of copper silicate within a silica matrix.

Uses & applications

Primarily used in jewelry (cabochons, bolo ties), ornamental carvings, and as a popular mineral specimen for collectors.

Geological facts

Highly prized varieties like 'Gem Silica' are considered the most valuable form of chalcedony. It is often mistaken for turquoise but is generally more translucent and greener.

Field identification & locations

Identify in the field by its distinctive vivid blue-green color associated with copper deposits (malachite, azurite). Hardness-test to distinguish it from pure chrysocolla (which is soft) versus silicified versions (which are hard). Found commonly in the southwestern US (Arizona), Peru, and the Congo.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral