mineral

Quartz (Smoky/Milky)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Grayish-brown to milky white; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Grayish-brown to milky white
Luster: Vitreous (glassy)

Identified July 19, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Grayish-brown to milky white; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Forms in igneous, metamorphic, and sedimentary environments through the cooling of magma or precipitation from hydrothermal veins. This specimen appears to be a water-worn or weathered pebble.

Uses & applications

Crucial for electronics (piezoelectric properties), glassmaking, construction sand, and as decorative gemstones or collector specimens.

Geological facts

Quartz is one of the most abundant minerals in Earth's crust. Smoky quartz gets its color from natural irradiation of aluminum-bearing quartz.

Field identification & locations

Identify by its ability to scratch glass and lack of cleavage. Common in riverbeds, mountains, and beaches worldwide. This small pebble is a typical find for casual rockhounding.