Orange Quartzite (or Salmon Quartzite)

Physical Properties

Hardness: 7 on Mohs scale; Color: Orange, salmon, or peach; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.63 - 2.65

Formation & Geological History

Formed through the metamorphism of quartz-rich sandstone. High heat and pressure from tectonic activity cause the individual sand grains to recrystallize and fuse together into a dense, hard mass.

Uses & Applications

Used as decorative stone in landscaping, aquarium gravel, crushed stone for road construction, and occasionally for lapidary work or polishing for collectors.

Geological Facts

Quartzite is so tough that it often outlasts the mountain ranges it forms. The orange color is typically due to trace amounts of iron oxide (hematite) staining the quartz grains during or after formation.

Field Identification & Locations

Identify in the field by its extreme hardness (it will easily scratch glass) and its grainy appearance that looks like sandpaper but feels smooth to the touch. Found globally in ancient mountain belts.

Identified on: 4/27/2026

Mode: Standard