mineral

Milky Quartz with Mineral Inclusions

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Translucent white to milky with black/grey banding; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture.

Hardness: 7 on Mohs scale
Color: Translucent white to milky with black/grey banding
Luster: Vitreous to greasy

Identified May 25, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Translucent white to milky with black/grey banding; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture.

Formation & geological history

Formed from silica-rich hydrothermal fluids cooling in veins or cavities within igneous or metamorphic host rocks. The dark bands likely represent structural fractures filled with iron, manganese oxides, or carbonaceous materials.

Uses & applications

Quartz is used extensively in glassmaking, electronics (piezoelectric properties), and as an abrasive. Polished river-worn specimens are popular in decorative landscaping and as beginner collectibles.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. This specific specimen shows 'water-worn' smoothing, indicating it was likely found in a riverbed or coastal area.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), lack of cleavage, and waxy luster. Common in mountainous regions, riverbeds, and gravel deposits worldwide.

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Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

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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]

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Green Apatite on Albite

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

mineral