mineral

Quartz crystal with Pyrite inclusions

Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)

Hardness: 7 (Quartz) / 6-6.5 (Pyrite); Color: White to translucent matrix with metallic gold inclusions; Luster: Vitreous to greasy (Quartz), Metallic (Pyrite); Crystal Structure: Trigonal (Quartz), Cubic (Pyrite); Cleavage: None (Quartz), Poor (Pyrite).

Hardness: 7 (Quartz) / 6-6
Color: White to translucent matrix with metallic gold inclusions
Luster: Vitreous to greasy (Quartz), Metallic (Pyrite)

Identified March 18, 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 through hydrothermal processes where mineral-rich hot fluids cool in veins or cavities within host rocks. It can form across various geological ages, often in metamorphic or igneous environments, particularly near tectonic boundaries.

Uses & applications

Used primarily as decorative collector specimens, metaphysical healing stones, and occasionally in jewelry as cabochons or tumbled stones to display the metallic inclusions.

Geological facts

Quartz is one of the most abundant minerals on Earth. When Pyrite is included, it is often called 'Fool\'s Gold' within the crystal. These specimens are prized by collectors for the contrast between the translucent matrix and metallic flakes.

Field identification & locations

Identify by checking for the hardness of quartz (cannot be scratched by a steel nail) and the distinct brassy-yellow metallic glints of pyrite. Commonly found in mountainous regions like the Alps, Andes, or specifically in areas like the Tri-State Mining district in the US.

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