mineral

Quartz Geode

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Clear to white crystals within a brownish-grey rind; Luster: Vitreous/glassy; Structure: Hexagonal (trigonal); Cleavage: None/conchoidal fracture; Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Clear to white crystals within a brownish-grey rind
Luster: Vitreous/glassy

Identified May 17, 2026More mineral →

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Physical properties

Formation & geological history

Formed as secondary mineral precipitates in hollow cavities within volcanic or sedimentary rocks. Over geological time, mineral-rich groundwater seeps into gas bubbles or hollows, crystallizing inward.

Uses & applications

Used primarily for ornamental purposes, healing crystal collections, educational specimens, and home decor. High-purity quartz is also used in the electronics and glass industries.

Geological facts

Geodes are essentially 'fossils' of mineral growth. The word geode comes from the Greek word 'Geoides' which means 'earth-like'. They can range from a few centimeters to several meters in size.

Field identification & locations

Identified in the field by their rounded, lumpy, or cauliflower-like stone exterior that feels unusually light for its size. Often found in deserts or riverbeds in states like Iowa, Missouri, and Utah.