mineral

Quartz geode

Quartz (SiO₂), likely a quartz-lined geode; the white crystals may include calcite

AI-generated identification · may be incorrect

Roughly spherical, hollow nodule with a gray outer rind and white, sparkling interior crystals. Quartz is Mohs 7, vitreous, and trigonal; calcite, if present, is Mohs 3 and rhombohedral.

Identified October 5, 2026More mineral →

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Physical properties

Roughly spherical, hollow nodule with a gray outer rind and white, sparkling interior crystals. Quartz is Mohs 7, vitreous, and trigonal; calcite, if present, is Mohs 3 and rhombohedral.

Formation & geological history

Forms when mineral-rich groundwater deposits crystals inside a cavity in volcanic or sedimentary rock. Geodes occur across many geological ages; the image alone cannot determine its age or exact composition.

Uses & applications

Popular as a decorative and collectible specimen; quartz is also used in glass, electronics, and jewelry.

Geological facts

The cavity formed before its crystals grew, often through repeated mineral deposition.

Field identification & locations

Identify by the hollow, crystal-lined interior and hard, glassy quartz points; common sources include Brazil, Uruguay, and the US Midwest. A photo cannot confirm whether the crystals are quartz or calcite.