metamorphic

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly microcrystalline quartz (SiO₂), with possible mica and iron-oxide inclusions

AI-generated identification · may be incorrect

Hardness about 7 Mohs; white, gray, tan, and brown mottled coloration with a vitreous to sugary luster. Interlocking quartz grains show no obvious cleavage and commonly fracture unevenly.

Identified September 16, 2026More metamorphic →

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At a glance

Common name: Quartz-rich metamorphic rock, likely quartzite
Scientific name: Quartzite; predominantly microcrystalline quartz (SiO₂), with possible mica and iron-oxide inclusions
Category: metamorphic
Identified: September 16, 2026
Method: Standard

AI Estimated Value

Approximately $2–$15 for a common hand specimen; exceptional colorful or well-crystallized examples may reach $25–$100.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Hardness about 7 Mohs; white, gray, tan, and brown mottled coloration with a vitreous to sugary luster. Interlocking quartz grains show no obvious cleavage and commonly fracture unevenly.

Formation & geological history

Formed when quartz-rich sandstone was recrystallized under elevated heat and pressure during mountain-building; individual specimens may range from Precambrian to younger geologic ages.

Uses & applications

Used as crushed stone, aggregate, paving, countertops, and decorative building stone; attractive pieces are collected, though this specimen appears common and unpolished.

Geological facts

Quartzite is typically harder and more resistant than its sandstone precursor. Brown coloration commonly results from iron-oxide staining, while shiny patches may be mica or reflective quartz fracture surfaces.

Field identification & locations

Identify it by its very hard, glassy texture and quartz grains fused across broken surfaces; unlike sandstone, it usually does not crumble along grain boundaries. Common in metamorphic mountain belts worldwide, including the United States, Brazil, India, and Scandinavia.