mineral

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Clear to milky white with some purple (amethystine) tints; Luster: Vitreous to waxy; Crystal structure: Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Clear to milky white with some purple (amethystine) tints
Luster: Vitreous to waxy

Identified June 16, 2026More mineral →

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Physical properties

Formation & geological history

Formed in volcanic or sedimentary cavities where mineral-rich groundwater deposits silica over thousands of years. Usually found in desert environments or limestone deposits.

Uses & applications

Used in gemstone collection, decorative home decor, crystal healing practices, and as educational geological specimens.

Geological facts

Geodes are known as 'treasure rocks' because they look like ordinary stones on the outside but contain beautiful crystal linings inside. This specimen appears to be a broken fragment showing the internal crystalline structure.

Field identification & locations

Look for rounded, nodular shapes with a lighter weight than solid rocks of the same size. Field identification involves looking for chalcedony rinds and interior voids. Commonly found in Brazil, Mexico, and the US (Iowa, Utah, Arizona).