metamorphic

Weathered quartz-rich rock, likely milky quartz or quartzite

Quartz (SiO₂); possibly quartzite, a metamorphosed quartz sandstone

AI-generated identification · may be incorrect

White to pale gray, dull to slightly glassy luster, massive texture, and no obvious cleavage; quartz has Mohs hardness 7, while quartzite is similarly hard and scratches glass. Brown patches are likely iron-oxide weathering or surface staining.

Identified September 2, 2026More metamorphic →

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Physical properties

Formation & geological history

If quartzite, it formed when quartz sandstone was compacted and recrystallized during metamorphism; if massive quartz, it precipitated from silica-rich hydrothermal fluids. The specimen’s exact age and origin cannot be determined from the photograph.

Uses & applications

Quartzite is used as durable building stone, aggregate, and landscaping material; clear quartz is used ornamentally and in electronics. This opaque, weathered piece has little jewelry value.

Geological facts

The rounded shape and worn surface suggest stream, beach, or glacial transport. A steel knife should not scratch it, while quartz or a glass plate may scratch it.

Field identification & locations

Commonly found in quartz veins, metamorphic terrains, river gravels, and glacial deposits worldwide; inspect a fresh broken edge for interlocking quartz grains to confirm quartzite.