mineral

Milky Quartz (Gold-bearing Prospecting Specimen)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Translucent white to milky white with iron oxidation/rust staining (ochre); Luster: Vitreous (glassy) to greasy; Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Luster: Vitreous (glassy) to greasy

Identified March 24, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed in hydrothermal veins where silica-rich fluids are injected into fractures in the surrounding host rock. Commonly found in orogenic belts. This specimen shows surface weathering indicating it was likely found in a riverbed or surface deposit (alluvial or eluvial).

Uses & applications

Used industrially in glass making, electronics (piezoelectric properties), and as an abrasive. In this form, it is primarily a geological specimen or ore sample for gold prospecting.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Specimens like this one, showing heavy iron staining and 'rotten' pockets, are historically used by prospectors as an indicator of potential gold mineralization.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife, its lack of cleavage planes, and its characteristic milky appearance. Found globally, especially in mountainous or volcanic regions. Tip: Look for 'vuggy' or pitted textures which may have once housed other minerals.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

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

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral