mineral
Quartz (Iron-Stained or Milky)
Silicon Dioxide (SiO2)
Hardness: 7 (Mohs scale), Color: White to tan/orange due to iron oxidation, Luster: Vitreous to greasy, Crystal structure: Trigonal/Hexagonal, Cleavage: None (Conchoidal fracture), Specific Gravity: 2.65
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Physical properties
Hardness: 7 (Mohs scale), Color: White to tan/orange due to iron oxidation, Luster: Vitreous to greasy, Crystal structure: Trigonal/Hexagonal, Cleavage: None (Conchoidal fracture), Specific Gravity: 2.65
Formation & geological history
Formed from cooling magma in igneous veins or through hydrothermal activity where silica-rich fluids permeate rock fractures. This specimen shows iron staining from weathering in iron-rich environments.
Uses & applications
Industrial use in glassmaking, abrasives, and electronics (piezoelectric). Also used for landscaping and as a base-level collector mineral.
Geological facts
Quartz is the second most abundant mineral in Earth's continental crust. It is chemically very stable, which is why it often remains as pebbles after other minerals have eroded away.
Field identification & locations
Identified in the field by its inability to be scratched by a steel knife and its lack of cleavage planes. Found globally in almost all geological environments.
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Mineral
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Mineral/Rock
Banded Gneiss (River Rock/Pebble)
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