mineral

Quartz (Smoky/Granular variety)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Tan to light brown; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (Conchoidal fracture); Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Tan to light brown
Luster: Vitreous to waxy

Identified June 3, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Tan to light brown; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (Conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed from silica-rich hydrothermal solutions or cooling magma. This small grain likely weathered out of a larger igneous rock like granite or a metamorphic rock like quartzite.

Uses & applications

Quartz is used in glass making, electronics (piezoelectric properties), abrasives, and as a gemstone. Small grains like this are common in construction sand/gravel.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is highly resistant to chemical and physical weathering, which is why it remains as sand grains long after other minerals have eroded.

Field identification & locations

Identify in the field by its ability to scratch glass and its lack of cleavage. Often found in riverbeds, beaches, and soil. Collectors look for larger, well-formed crystal points or distinct colors.

Other mineral specimens

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Biotite Schist

Biotite-rich Schist [K(Mg,Fe)3AlSi3O10(F,OH)2]

metamorphic