mineral

Quartz Geode with Goethite/Hematite

Silicon Dioxide (SiO2) with Iron Oxides

Hardness: 7 (Mohs scale), Color: Clear to smoky gray crystals on reddish-brown matrix, Luster: Vitreous/Glassy, Crystal Structure: Trigonal/Hexagonal, Cleavage: None/Conchoidal, Specific Gravity: 2.65

Identified May 4, 2026More mineral →

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Physical properties

Formation & geological history

Formed by the precipitation of mineral-rich groundwater in cavities of volcanic or sedimentary rocks. The presence of red/brown coloration stems from iron oxide inclusions (Hematite/Goethite).

Uses & applications

Primarily used as decorative display specimens, educational tools, and by mineral collectors.

Geological facts

Geodes are essentially hollow rocks filled with crystals; this specimen shows a transition from clear quartz to iron-stained areas, creating a 'smoky' or 'morion' appearance in the darker zones.

Field identification & locations

Identify in the field by looking for rounded nodules that are lighter than similar-sized solid rocks. Found globally, especially in volcanic ash beds and limestone regions like the American Midwest or Brazil.

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