mineral
Quartz (Milky/Smoky variety)
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness: 7 on Mohs scale. Color: Translucent to opaque white, tan, and gray. Luster: Vitreous to greasy. Crystal structure: Hexagonal/Trigonal. Cleavage: Indistinct (conchoidal fracture). Specific Gravity: 2.65.
- Hardness
- 7 on Mohs scale
- Color
- Translucent to opaque white, tan, and gray
- Luster
- Vitreous to greasy
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Physical properties
Hardness: 7 on Mohs scale. Color: Translucent to opaque white, tan, and gray. Luster: Vitreous to greasy. Crystal structure: Hexagonal/Trigonal. Cleavage: Indistinct (conchoidal fracture). Specific Gravity: 2.65.
Formation & geological history
Forms in a wide range of environments, primarily through the cooling and crystallization of silica-rich magma or from hydrothermal veins. It is found in igneous, metamorphic, and sedimentary rocks.
Uses & applications
Used in glassmaking, electronics (piezoelectric properties), abrasives, construction aggregates, and as a semi-precious gemstone in jewelry and carving.
Geological facts
Quartz is the second most abundant mineral in Earth's continental crust. It is highly resistant to chemical and physical weathering, which is why it often makes up the majority of river and beach sand.
Field identification & locations
Identify in the field by its hardness (it can scratch glass), lack of cleavage, and glassy appearance. It is found globally across all continents in mountainous and rocky terrain.
