Rock Identifier
Druzy Quartz Geode (Silicon Dioxide (SiO2)) — mineral
mineral

Druzy Quartz Geode

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Clear to white crystals on a grey/black matrix; Luster: Vitreous/glassy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness
7 on Mohs scale
Color
Clear to white crystals on a grey/black matrix
Luster
Vitreous/glassy
Identified More mineral

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Physical properties

Hardness: 7 on Mohs scale; Color: Clear to white crystals on a grey/black matrix; Luster: Vitreous/glassy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the precipitation of silica-saturated groundwater within volcanic or sedimentary cavities/bubbles (vesicles). Over thousands of years, the cooling and mineral deposition result in the growth of tiny crystals on the inner surface. These can date back to various geological periods including the Cretaceous or Tertiary.

Uses & applications

Primarily used for jewelry making (pendants and rings), metaphysical collecting, and ornamental decorative pieces in homes.

Geological facts

The word 'druse' refers to a coating of fine crystals on a rock fracture or surface. Quartz is the most common druzy mineral, but others like garnet and malachite can also form this way. Famous geodes are often found in Brazil, Uruguay, and the Midwestern United States.

Field identification & locations

Look for a rough, unassuming exterior resembling a plain rock, but with a hollow or semi-hollow center filled with sparkling, sugar-like crystals. In the field, shaking a round rock to see if it feels hollow or rattles can indicate a geode.