Quartzite

Hardness: 7 (Mohs scale); Color: Pinkish-orange, peach, cream, and white; Luster: Vitreous to waxy; Structure: Granular/Massive; Cleavage: None (conchoidal fracture); Specific Gravity: 2.63-2.65

Formed from the metamorphism of quartz-rich sandstone. High heat and pressure Recrystallize quartz grains into a dense, interlocking mosaic of crystals. Most deposits range from Proterozoic to Paleozoic eras.

Used as decorative stone, crushed stone for road construction, railway ballast, and occasionally as a gemstone in tumbled jewelry or carvings.

Quartzite is so tough that it often outlasts the surrounding rock in weathering processes, forming prominent ridges and hills. It is often confused with marble, but can be distinguished by its inability to be scratched by metal and lack of reaction to acid.

Identify by its extreme hardness (it will scratch glass) and its grainy, sandpaper-like appearance under magnification, even when smooth. Found globally in mountainous regions where tectonic activity occurs. Collectors should look for unique banding or iron-staining which creates the peach/pink hues seen here.