mineral

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: White to colorless crystals in a brown matrix; Luster: Vitreous (glassy) to dull; Crystal Structure: Hexagonal (trigonal); Cleavage: None; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: White to colorless crystals in a brown matrix
Luster: Vitreous (glassy) to dull

Identified July 15, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: White to colorless crystals in a brown matrix; Luster: Vitreous (glassy) to dull; Crystal Structure: Hexagonal (trigonal); Cleavage: None; Specific Gravity: 2.65

Formation & geological history

Formed in volcanic or sedimentary cavities where silica-rich groundwater precipitates crystals over long periods. Often found in basaltic lava flows or limestone beds.

Uses & applications

Primarily used for mineral collecting, home decor, and as educational specimens. High-purity quartz is used in electronics and glass manufacturing.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Geodes like this often look like ordinary rocks on the outside but contain hollow cavities lined with crystals.

Field identification & locations

Identify by its hardness (will scratch glass) and crystalline structure. Common in regions with high volcanic activity or ancient seabed deposits like the American Midwest or Brazil.