mineral

Quartz (Milky/Smoky Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale. Color: Translucent to opaque white, pale smoky grey, or light tan. Luster: Vitreous (glassy) to greasy. Crystal System: Trigonal. Cleavage: None, exhibits conchoidal to uneven fracture. Specific Gravity: ~2.65.

Hardness: 7 on the Mohs scale
Color: Translucent to opaque white, pale smoky grey, or light tan
Luster: Vitreous (glassy) to greasy

Identified July 26, 2026More mineral →

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Physical properties

Formation & geological history

Forms in igneous rocks like granite and pegmatites, as well as hydrothermal veins and metamorphic rocks. It crystallizes from silica-rich fluids over a wide range of temperatures and pressures.

Uses & applications

Used widely in electronics (piezoelectric quartz oscillators), glassmaking, abrasives, decorative carvings, landscaping, and gemstone jewellery.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is completely clear (rock crystal), while inclusions, micro-cavities, or natural radiation produce varieties like milky quartz, smoky quartz, amethyst, and citrine.

Field identification & locations

Easily identified by its glass-like lustre, inability to be scratched by a steel knife (Mohs 7), lack of cleavage, and characteristic fracture pattern. Found in abundance globally.