mineral

Quartz Geode

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: White to colorless; Luster: Vitreous/glassy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: White to colorless
Luster: Vitreous/glassy

Identified June 2, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: White to colorless; Luster: Vitreous/glassy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Formed as hollow cavities in volcanic ash or sedimentary rock which are later filled by hydrothermal fluids or groundwater rich in dissolved minerals. As the water cools or evaporates, crystals grow inward from the walls of the cavity.

Uses & applications

Used primarily for ornamental displays, decorative centerpieces, geological education, and mineral collecting. Larger pieces can be used in metaphysical practices.

Geological facts

The word geode comes from the Greek word 'Geoides' meaning earth-like. Unlike a vug, which is a cavity in a vein, a geode is a discrete rounded unit that can detach from its host rock.

Field identification & locations

Identify in the field by looking for rounded, bumpy nodules that feel lighter than solid rocks of the same size. They are commonly found in desert regions of Morocco, Mexico, and the United States (notably Iowa and Utah).