mineral

Quartz Geode

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White, colorless, or smoky; Luster: Vitreous; Crystal structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White, colorless, or smoky
Luster: Vitreous

Identified June 19, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White, colorless, or smoky; Luster: Vitreous; Crystal structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Formation & geological history

Formed in cavities within sedimentary or volcanic rocks. Mineral-rich groundwater seeps into hollow spaces (vugs) and precipitates crystals over millions of years.

Uses & applications

Primarily used for mineral collecting, home decor, and spiritual/metaphysical purposes. Industrial quartz is used in electronics and glassmaking.

Geological facts

Geodes are essentially 'petrified bubbles.' While the exterior looks like an ordinary rock, the interior reveals a hollow cavity lined with sparkling crystals.

Field identification & locations

Identify in the field by looking for rounded, bumpy stones that feel lighter than they look (indicating a hollow center). Common in areas with limestone or volcanic ash layers.