metamorphic
Quartzite
Quartzite; predominantly microcrystalline quartz (SiO₂)
AI-generated identification · may be incorrectHardness 7 Mohs; pale gray, pink, and white with sugary granular texture and iron-oxide staining. Vitreous to dull luster, massive structure, and little or no cleavage; typically very dense and resistant to scratching.
Identified More metamorphic →
Explore Quartzite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness 7 Mohs; pale gray, pink, and white with sugary granular texture and iron-oxide staining. Vitreous to dull luster, massive structure, and little or no cleavage; typically very dense and resistant to scratching.
Formation & geological history
Formed when quartz-rich sandstone recrystallized under intense heat and pressure, generally during regional metamorphism. Its precise age cannot be determined from the image; quartzite occurs in rocks ranging from Precambrian to younger periods.
Uses & applications
Used as crushed stone, road aggregate, building stone, countertops, and decorative landscaping material; attractive pieces are collected but rarely gem-grade.
Geological facts
Quartzite commonly preserves faint sedimentary banding while individual quartz grains have fused into a hard mosaic. Pink or reddish tones usually reflect hematite or other iron oxides.
Field identification & locations
Likely quartzite based on its hardness, rounded weathering, and interlocking pale grains with pink bands; it should scratch glass and resist a steel knife. Common in metamorphic mountain belts worldwide, including the Appalachians, Rocky Mountains, and Precambrian shields.
More like this
