metamorphic

Iron-stained quartz-rich rock, possibly quartzite

Quartzite (tentative; predominantly quartz, SiO₂)

AI-generated identification · may be incorrect

Rough, opaque specimen with white to rusty-brown patches and a granular texture. Quartz has Mohs hardness 7, vitreous luster, and no cleavage; the image alone cannot confirm the rock’s composition or exact properties.

Identified October 5, 2026More metamorphic →

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Physical properties

Formation & geological history

Quartzite forms when quartz sandstone is recrystallized by heat and pressure during metamorphism; iron oxides can produce rusty coloration. Its age and formation setting cannot be determined from the photograph.

Uses & applications

Quartzite is used as crushed stone, building and decorative stone, and sometimes as a silica source. This small, unverified specimen has modest display or collecting value.

Geological facts

The specimen’s pale areas may be quartz, while the brown-red staining may be iron oxides; visual appearance alone is not enough to distinguish quartzite from other quartz-rich rocks.

Field identification & locations

Look for interlocking quartz grains and a hard surface that resists scratching by a steel knife; acid testing is not diagnostic. Quartzite occurs worldwide in metamorphic belts and near altered sandstone formations.