metamorphic

Iron-stained quartzite or quartz-rich sandstone

Quartzite, predominantly SiO₂, with iron-oxide coatings (hematite/goethite)

AI-generated identification · may be incorrect

Hardness about 7 Mohs; tan, rusty orange, and cream; dull to weakly vitreous luster; granular, interlocking quartz texture with irregular fracture and little or no cleavage. The rusty color indicates iron-oxide weathering or cement.

Identified September 2, 2026More metamorphic →

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Physical properties

Formation & geological history

Likely formed when quartz-rich sandstone was metamorphosed and recrystallized under heat and pressure, then oxidized during surface weathering; its exact geological age cannot be determined from the image. If grains remain distinct and friable, it may instead be iron-stained sandstone.

Uses & applications

Used as durable building stone, aggregate, riprap, and landscaping material; attractive pieces may be collected, but this specimen has limited gem value.

Geological facts

Quartzite commonly resists weathering more strongly than surrounding rock, forming ridges and resistant outcrops. Iron oxides can produce vivid red, orange, and brown surface colors.

Field identification & locations

Look for quartz grains fused into a hard mass; a steel nail should not scratch fresh quartz-rich surfaces, while sandstone may crumble or scratch more easily. Common in metamorphic mountain belts worldwide.