metamorphic

Quartz-rich rock, likely quartzite or milky quartz fragment

Quartzite; predominantly quartz (SiO₂)

AI-generated identification · may be incorrect

White to pale gray, dull-to-glassy luster, granular texture, and no obvious cleavage; quartz hardness is Mohs 7, with specific gravity about 2.65. The specimen appears fine-grained and weathered, though the photo cannot confirm whether it is quartzite rather than massive quartz or a quartz-rich sandstone.

Identified September 8, 2026More metamorphic →

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Physical properties

Formation & geological history

Quartzite forms when quartz-rich sandstone is recrystallized during metamorphism, commonly from Precambrian to younger mountain-building events; massive quartz forms from hydrothermal veins. Commonly found in metamorphic belts, stream gravels, and eroded vein outcrops.

Uses & applications

Crushed quartzite is used for aggregate, road material, and construction stone; attractive pieces may be used as landscaping or cabinet specimens. It is generally not gem-quality.

Geological facts

A steel knife should not scratch it, while quartz can scratch glass. Quartzite breaks across fused grains, whereas sandstone tends to break around individual grains and may feel gritty.

Field identification & locations

Look for a hard, pale rock with interlocking quartz grains and little porosity; a streak test is white. Common sources include mountain terrains and quartz-rich river deposits.