mineral

Milky quartz with iron-oxide staining

Quartz (silicon dioxide, SiO₂)

AI-generated identification · may be incorrect

Hardness 7 Mohs; translucent white to honey-brown, vitreous to greasy luster, massive rather than visibly crystalline, and no cleavage (irregular conchoidal fracture). Brown coloration likely comes from iron oxides or included material.

Identified August 7, 2026More mineral →

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Physical properties

Formation & geological history

Quartz crystallized from silica-rich hydrothermal fluids or grew in an igneous/metamorphic vein; the specimen’s exact age and locality cannot be determined from the image. Weathering likely produced the surface staining.

Uses & applications

Common quartz is used in glass, ceramics, abrasives, electronics, and engineered stone; attractive pieces are collected or occasionally cut as ornamental material. This rough fragment appears to have modest commercial value.

Geological facts

Quartz is one of Earth’s most abundant minerals and is chemically identical to clear rock crystal, amethyst, citrine, and smoky quartz; trace impurities and irradiation create many color varieties.

Field identification & locations

Look for glassy luster, white translucency, irregular fracture, and resistance to scratching; it should scratch ordinary glass but not be scratched by a steel knife. Common worldwide, especially in veins, cavities, granite, and metamorphic rocks.