mineral
Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Hardness: 7 on Mohs scale; Color: Clear to white; Luster: Vitreous (glassy); Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
- Hardness
- 7 on Mohs scale
- Color
- Clear to white
- Luster
- Vitreous (glassy)
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Physical properties
Hardness: 7 on Mohs scale; Color: Clear to white; Luster: Vitreous (glassy); Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
Formation & geological history
Formed through the cooling of magma or by hydrothermal precipitation from hot water solutions in veins. It is found in igneous, metamorphic, and sedimentary environments worldwide.
Uses & applications
Used extensively in electronics for frequency control, glassmaking, abrasives, construction as sand, and as a gemstone for jewelry and ornamental carvings.
Geological facts
Quartz is the second most abundant mineral in Earth's continental crust. It is piezoelectric, meaning it can generate an electric charge when mechanical pressure is applied.
Field identification & locations
Identify by its hardness (it will scratch glass), its lack of cleavage, and common six-sided prismatic crystals. It is found almost everywhere, particularly in mountainous regions and riverbeds.
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Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Sandstone with Mineral Veining or Crust
Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)
sedimentary
Schist
Schist
Metamorphic
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Nephrite Jade
Nephrite
Mineral/Rock