Quartzite

Physical Properties

Hardness: 7 (Mohs scale), Color: White to light grey, Luster: Vitreous to dull, Crystal Structure: Hexagonal (trigonal) system within grains, Cleavage: None/Conchoidal fracture, Specific Gravity: 2.6-2.7.

Formation & Geological History

Formed through the metamorphism of quartz-rich sandstone under intense heat and pressure over millions of years, often in orogenic (mountain-building) belts.

Uses & Applications

Used as decorative stone in construction, road ballast, kitchen countertops, and as a raw material for glass and ceramics.

Geological Facts

Quartzite is so durable that it can survive extreme weathering and often caps mountain ridges. It is harder than steel and can scratch glass easily.

Field Identification & Locations

Identify in the field by its sugary texture and extreme hardness; it will not react with acid like marble. Found globally in ancient shield areas and mountain ranges.

Identified on: 5/1/2026

Mode: Standard