mineral

Quartz (Milky or Cloudy variety)

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on the Mohs scale. Color: Translucent grey to milky white with yellowish iron oxidation. Luster: Vitreous (glassy) to waxy. Crystal Structure: Hexagonal (trigonal) system. Cleavage: None (conchoidal fracture). Specific Gravity: Approx 2.65.

Hardness: 7 on the Mohs scale
Luster: Vitreous (glassy) to waxy

Identified March 29, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of silica-rich magma in igneous rocks like granite, or through hydrothermal precipitation in veins. These specimens are often millions of years old and have been rounded by water transport (fluvial or beach action).

Uses & applications

Industrial uses include glassmaking, electronics (piezoelectric properties), and abrasives. In collecting, it is used for lapidary work, cabochons, and decorative landscaping.

Geological facts

Quartz is the most abundant mineral in the Earth's continental crust. It is highly resistant to chemical weathering, which is why it often remains as pebbles long after other minerals have eroded away.

Field identification & locations

Identify in the field by its ability to scratch glass, its lack of cleavage (it breaks in curved shards), and its glassy luster. It is commonly found in riverbeds, beaches, and mountainous regions worldwide.

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