Quartzite Pebble

Hardness of 7 on the Mohs scale, color ranges from off-white and tan to pinkish or grey, vitreous to greasy luster, massive to granular crystal structure, no good cleavage, specific gravity of approximately 2.65

Formed from quartz-rich sandstone or chert that has been subjected to heat and pressure through regional or contact metamorphism, fusing quartz grains together over millions of years

Used in landscaping, decorative stone, construction aggregate, and occasionally in glassmaking or as crushed stone for road bases

Quartzite is extremely durable and resistant to chemical weathering, which is why it often survives as smooth, rounded pebbles in riverbeds and beaches long after less resistant rocks have eroded away

Can be identified by its extreme hardness (it will easily scratch glass and cannot be scratched by a steel knife) and the sugary, interlocking quartz grains visible on broken surfaces; commonly found in river gravels, glacial tills, and ancient mountain belts worldwide