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

Quartz Geode / Druzy Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White, clear, yellowish/rusty due to iron oxide; Luster: Vitreous/glassy; Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness
7 (Mohs scale)
Color
White, clear, yellowish/rusty due to iron oxide
Luster
Vitreous/glassy
Identified More mineral

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Physical properties

Hardness: 7 (Mohs scale); Color: White, clear, yellowish/rusty due to iron oxide; Luster: Vitreous/glassy; Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed by the precipitation of quartz from hydrothermal fluids or mineral-rich groundwater within a cavity (vug) in a host rock, typically volcanic or sedimentary. The outer layer is likely a stony matrix of chalcedony or basalt.

Uses & applications

Used primarily for decorative purposes, high-quality gemstone jewelry, metaphysical collecting, and as educational geological specimens.

Geological facts

Geodes are rocks that appear plain on the outside but contain hollow cavities lined with crystals. This specific piece is a fragment of a larger geode showing druzy crystals and massive quartz layers.

Field identification & locations

Identified in the field by its rounded exterior shape (if whole) and the presence of sparkling crystal faces inside a void. Commonly found in desert regions or volcanic deposits like those in Brazil, Morocco, or the US Midwest.