mineral

Milky Quartz with Iron Staining and Matrix

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Opaque white with orange/red iron staining and grey lithic matrix; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Luster: Vitreous to greasy

Identified April 17, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal fluids cooling in veins or cavities within the earth's crust. It can form in various temperatures and pressures across most geological eras.

Uses & applications

Used in glass manufacturing, electronics (due to piezoelectric properties), construction aggregates, and widely collected as mineral specimens or decorative stones.

Geological facts

Quartz is the most abundant mineral in the Earth's continental crust. The 'milky' appearance is caused by tiny inclusions of gas or liquid trapped during the crystal's growth.

Field identification & locations

Identify by its hardness (it will easily scratch glass) and lack of cleavage (it breaks in irregular, curved 'conchoidal' patterns). Common in mountainous regions and riverbeds.

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

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral