metamorphic
Pale rounded quartz-rich pebble, likely quartzite
Quartzite (mostly microcrystalline SiO₂), possibly quartz-rich sandstone or vein quartz
AI-generated identification · may be incorrectHardness about 7 Mohs; cream to pale yellow, dull-to-waxy surface with faint granular texture and minor dark inclusions. Quartzite is non-cleavable, compact, and typically has a specific gravity near 2.65; exact identification requires a scratch test and close examination.
Identified More metamorphic →
Explore Pale rounded quartz-rich pebble, likely quartzite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness about 7 Mohs; cream to pale yellow, dull-to-waxy surface with faint granular texture and minor dark inclusions. Quartzite is non-cleavable, compact, and typically has a specific gravity near 2.65; exact identification requires a scratch test and close examination.
Formation & geological history
Likely formed when quartz-rich sandstone was recrystallized under metamorphic heat and pressure, commonly during mountain-building; its rounded shape indicates later stream or beach transport. Geological age cannot be determined from the photograph.
Uses & applications
Used as aggregate, landscaping stone, road material, and decorative stone; attractive pieces may be polished or collected, though this specimen appears common.
Geological facts
Quartzite commonly resembles quartz, but its interlocking grains give it a sugary fracture and great durability. A steel file should not scratch it; glass-scratch testing is useful but may damage the specimen.
Field identification & locations
Common in metamorphic belts and derived gravels worldwide, including the Appalachian, Rocky, and other mountain regions. Look for uniform quartz grains, no obvious sedimentary layering, and resistance to scratching; a vinegar test is not diagnostic.
More like this
