mineral

Milky Quartz in Epidote Host Rock

Crystalline Silicon Dioxide (SiO2) with Epidote Ca2(Al,Fe)3(SiO4)3(OH)

Hardness: 7 (Quartz) / 6-7 (Epidote); Color: Opaque white and dull green; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (Quartz) / Monoclinic (Epidote); Cleavage: None (Quartz) / Perfect in one direction (Epidote)

Hardness: 7 (Quartz) / 6-7 (Epidote)
Color: Opaque white and dull green
Luster: Vitreous to greasy

Identified June 15, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins or via metamorphic processes where silica-rich fluids permeate existing rock. This specimen appears to be a river-worn cobble, smoothed by water erosion.

Uses & applications

Commonly used as an ornamental stone, for landscaping, or in the manufacturing of glass and ceramics. Also used as a metaphysical stone.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The green epidote often indicates hydrothermal alteration of igneous rocks.

Field identification & locations

Identify in the field by its hardness (will scratch glass), white milky color, and translucent to opaque light transmission. Commonly found in riverbeds and mountainous regions.

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