mineral
Quartz
Silicon Dioxide (SiO2)
Hardness: 7 (Mohs scale), Color: Colorless to white/cloudy, Luster: Vitreous (glassy) to greasy, Crystal structure: Trigonal (often hexagonal prisms), Cleavage: None/Conchoidal fracture, Specific gravity: 2.65
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Physical properties
Hardness: 7 (Mohs scale), Color: Colorless to white/cloudy, Luster: Vitreous (glassy) to greasy, Crystal structure: Trigonal (often hexagonal prisms), Cleavage: None/Conchoidal fracture, Specific gravity: 2.65
Formation & geological history
Forms through crystallization of magma or precipitation from hydrothermal veins. Found in igneous, metamorphic, and sedimentary rocks across all geological ages.
Uses & applications
Used in glass making, electronics (piezoelectric properties), abrasives, watches, and jewelry as gemstones (amethyst, citrine, etc.).
Geological facts
It is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'Quarz', which originally meant 'hard'.
Field identification & locations
Identify by its inability to be scratched by a steel knife and its lack of cleavage (it breaks in curved, shell-like patterns). Found globally in riverbeds, mountains, and beaches.
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Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Nephrite Jade
Nephrite
Mineral/Rock
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety often found as a river rock)
Metamorphic Rock
![Biotite Schist (Biotite-rich Schist [K(Mg,Fe)3AlSi3O10(F,OH)2]) — metamorphic](https://media.rock.id/9ca564b5-bc87-402b-965a-69b21f9aa6bf-thumbnail.jpg)
Biotite Schist
Biotite-rich Schist [K(Mg,Fe)3AlSi3O10(F,OH)2]
metamorphic