mineral

Quartz (Milky/Macro-crystalline)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: White to translucent; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (Trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: White to translucent
Luster: Vitreous to greasy

Identified June 1, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: White to translucent; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (Trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Found in all types of geological environments; commonly forms from hydrothermal veins, cooling magma (pegmatites), or as a primary mineral in igneous rocks like granite. It is abundant across all geological ages.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, construction sand, and as common gemstones/decorative items.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is clear, but impurities or fluid inclusions create varieties like Milky Quartz, Amethyst, and Citrine.

Field identification & locations

Identify by its ability to scratch glass and lack of cleavage planes. Found globally in riverbeds, mountains, and beaches. Collectors look for well-defined hexagonal crystal points or unique terminations.

Other mineral specimens

See all

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