mineral

Quartz Geode

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Clear to milky white; Luster: Vitreous (glassy); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Clear to milky white
Luster: Vitreous (glassy)

Identified April 28, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Clear to milky white; Luster: Vitreous (glassy); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed as secondary mineral precipitates in hollow cavities (vesicles) of volcanic or sedimentary rocks. Over millions of years, mineral-rich groundwater seeps into these cavities, allowing crystals to grow inward toward the center.

Uses & applications

Primarily used for decorative purposes, collecting, jewelry (as cabochons or drusy), and in metaphysical practices. Industrial quartz is used in electronics and glassmaking.

Geological facts

The word geode comes from the Greek word 'Geoides' meaning earth-like. Unlike a nodule, which is solid throughout, a geode has a hollow or crystal-filled interior cavity.

Field identification & locations

Identify by its bumpy, round exterior that looks like an ordinary rock but feels lighter than a solid rock of the same size. Found globally in desert regions and limestone/volcanic ash beds.