Quartzite with Hematite staining

Physical Properties

Hardness: 7 on Mohs scale; Color: typically white to gray with pink/red/orange staining from hematite; Luster: vitreous to dull; Crystal structure: hexagonal (trigonal); Cleavage: none (conchoidal fracture).

Formation & Geological History

Formed through the regional or contact metamorphism of quartz-rich sandstone. High heat and pressure cause the sand grains to recrystallize into an interlocking mosaic. The red coloring occurs due to the introduction of iron oxides during or after formation.

Uses & Applications

Used as crushed stone for road construction, railroad ballast, and building stone. Fine specimens are sometimes used for lapidary work or landscape decoration.

Geological Facts

Quartzite is so strong that when it breaks, it breaks through the quartz grains rather than along the boundaries between them, unlike sandstone.

Field Identification & Locations

Identify in the field by its extreme hardness (cannot be scratched by a steel knife) and its grainy but crystalline 'sugary' texture. Found globally in mountainous regions and on beaches derived from those regions.

Identified on: 5/3/2026

Mode: Standard