mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs), Color: Colorless/Transparent, Luster: Vitreous (glassy), Crystal Structure: Hexagonal/Trigonal, Cleavage: Indistinct/Conchoidal fracture, Specific Gravity: 2.65

Identified July 10, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs), Color: Colorless/Transparent, Luster: Vitreous (glassy), Crystal Structure: Hexagonal/Trigonal, Cleavage: Indistinct/Conchoidal fracture, Specific Gravity: 2.65

Formation & geological history

Quartz forms in a wide variety of environments, most commonly by crystallizing from cooling magma or precipitation from hydrothermal veins. It is a major component of igneous rocks like granite and metamorphic rocks like quartzite.

Uses & applications

Used in jewelry, watchmaking (piezoelectric properties), glassmaking, electronics, and as a popular specimen for crystal collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the Greek word 'krystallos', meaning ice, as ancient peoples believed quartz was ice that had frozen so hard it would never melt.

Field identification & locations

Identified by its 7 hardness (scratches glass but not vice-versa), hexagonal prism shape, and lack of cleavage. Found globally, especially in mountainous regions like the Alps, Brazil, and Arkansas, USA.