mineral

Quartz (Milky/Smoky variety)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Translucent greyish-white; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Translucent greyish-white
Luster: Vitreous to greasy

Identified June 23, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Translucent greyish-white; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. This water-worn specimen likely originated from a vein and was subsequently weathered and transported by water.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, and as a common gemstone or collector's specimen.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is chemically and physically very resistant to weathering, which is why it often persists as pebbles in riverbeds.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), lack of cleavage, and waxy/vitreous luster. Common in riverbeds and mountainous terrain worldwide.