mineral

Quartz (Milky or Smoky variant)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Colorless to white/grey with iron staining; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Colorless to white/grey with iron staining
Luster: Vitreous (glassy)

Identified May 29, 2026More mineral →

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Physical properties

Formation & geological history

Formed in igneous, metamorphic, and sedimentary environments through the cooling of magma or precipitation from hydrothermal fluids. This specific specimen shows iron oxide staining common in surface-altered quartz veins.

Uses & applications

Used extensively in glassmaking, electronics (piezoelectric properties), abrasives, and as a semi-precious gemstone in jewelry and pocket stones.

Geological facts

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

Field identification & locations

Identified by its ability to scratch glass and steel, its lack of cleavage (breaks like glass), and its glassy luster. It is found globally, particularly in mountain ranges and riverbeds.

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

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Epidote

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Nephrite Jade

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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]

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