mineral

Quartz Geode (Druzy Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Colorless to white/gray; Luster: Vitreous (glassy) to adamantine; Crystal structure: Trigonal/Hexagonal; Cleavage: None; Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Colorless to white/gray
Luster: Vitreous (glassy) to adamantine

Identified May 27, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Colorless to white/gray; Luster: Vitreous (glassy) to adamantine; Crystal structure: Trigonal/Hexagonal; Cleavage: None; Specific gravity: 2.65

Formation & geological history

Formed by the precipitation of mineral-rich water within hollow cavities in volcanic or sedimentary rocks. Over geological time (millions of years), silica crystallizes on the inner walls of the cavity.

Uses & applications

Commonly used for lapidary work, home decor, ornamental lapidary, and as a popular specimen for mineral collectors and educational purposes.

Geological facts

Geodes are like nature's 'surprise eggs'; their drab, lumpy exterior hides a sparkling crystalline interior. The word 'geode' comes from the Greek 'geoides' meaning 'earth-like'.

Field identification & locations

Identified by a rounded, lumpy, rock-like exterior that is unusually light for its size. In the field, look for hollow nodules in limestone or volcanic ash deposits. Common in regions like Morocco, Brazil, and the Midwestern United States.