Quartzite Pebble

Hardness: 7 (Mohs), Color: brownish-orange to tan (iron staining), Luster: dull to vitreous, Crystal structure: Trigonal (microcrystalline), Cleavage: None/Conchoidal fracture

Formed from the metamorphism of quartz-rich sandstone under intense heat and pressure. This specific specimen is river-rounded, indicating post-metamorphic erosion and transport by water.

Used primarily as decorative gravel, in landscaping, aquarium decor, and as a durable construction aggregate. Exceptional specimens are sometimes used as tumble-stones for beginners in lapidary.

Quartzite is so hard that it will scratch glass and even steel. It is one of the most chemically and physically resistant rocks found on Earth's surface, which is why it often survives as rounded pebbles long after other rocks have eroded away.

Identify by its hardness (cannot be scratched by a knife) and sugary, granular texture hidden beneath the smooth surface. Common in riverbeds, glacial tills, and beach deposits globally.