Quartz Geode with Calcite

Physical Properties

Quartz: Hardness 7, colorless to white, vitreous luster. Calcite: Hardness 3, rhombohedral cleavage, pale color.

Formation & Geological History

Formed in vesicles of volcanic rocks or sedimentary cavities where mineral-rich groundwater precipitated the crystals over long geological periods.

Uses & Applications

Collectible specimen, decorative piece, metaphysical applications.

Geological Facts

Geodes are typically hollow, spherical rocks with a cavity lined with crystals. The presence of large blocky calcite crystals growing on the finer quartz druzy is a classic paragenesis.

Field Identification & Locations

Identified by the rough, non-descript outer rind contrasting with the crystalline interior. Calcite can be distinguished from quartz by its lower hardness and cleavage.

Identified on: 4/26/2026

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