mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Hardness: 7 (Mohs scale); Color: Colorless; Luster: Vitreous (glassy); Crystal structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65
- Hardness
- 7 (Mohs scale)
- Color
- Colorless
- Luster
- Vitreous (glassy)
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Physical properties
Hardness: 7 (Mohs scale); Color: Colorless; Luster: Vitreous (glassy); Crystal structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65
Formation & geological history
Formed from cooling of silica-rich magma or from hydrothermal veins. It is one of the most abundant minerals in the Earth's crust and can be found in almost all geological environments.
Uses & applications
Used in electronics (oscillators), optics, glassmaking, construction (as sandpaper or in concrete), and widely in jewelry and alternative healing practices.
Geological facts
Quartz is piezo-electric, meaning it generates an electric charge when mechanical pressure is applied. Ancient Greeks believed rock crystal was permanently frozen ice.
Field identification & locations
Identify in the field by its hardness (scratches glass), lack of cleavage, and hexagonal crystal habit. Found globally, especially in mountainous regions like the Alps, Arkansas (USA), and Brazil.
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Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
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
Granite
Granite (Phaneritic intrusive igneous rock)
igneous