Yellow Quartzite

Physical Properties

Hardness: 7 (Mohs scale); Color: Yellow to brownish-yellow due to iron oxide impurities; Luster: Vitreous to waxy; Structure: Granular/Crystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.7

Formation & Geological History

Formed through the metamorphism of quartz-rich sandstone. High heat and pressure from tectonic activity cause the sand grains to recrystallize and fuse together, typically in orogenic belts of various geological ages.

Uses & Applications

Used in construction as crushed stone or decorative ballast, as dimension stone in architecture, and occasionally as an ornamental stone in jewelry (tumbled stones or cabochons).

Geological Facts

Quartzite is often harder than the sandstone it originated from and is extremely resistant to chemical weathering, which is why it often forms the tops of ridges and hills.

Field Identification & Locations

Identify in the field by its sugary texture and extreme hardness (it will easily scratch glass and steel knives). Common in Appalachian regions and ancient shield areas. It differs from quartz by its internal grainy texture.

Identified on: 4/27/2026

Mode: Standard