metamorphic
Yellow Quartzite (Iron-Stained)
Quartzite (primarily SiO2 with iron oxide impurities)
Hardness: 7 (Mohs scale); Color: Yellow to orange-brown; Luster: Vitreous to waxy; Structure: Granular/Crystalline; Cleavage: None; Specific Gravity: 2.6–2.7
- Hardness
- 7 (Mohs scale)
- Color
- Yellow to orange-brown
- Luster
- Vitreous to waxy
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 (Mohs scale); Color: Yellow to orange-brown; Luster: Vitreous to waxy; Structure: Granular/Crystalline; Cleavage: None; Specific Gravity: 2.6–2.7
Formation & geological history
Formed from the metamorphism of quartz sandstone under intense heat and pressure. The yellow coloration is due to the presence of secondary iron oxides (limonite or goethite) that have stained the silica lattice or permeated the grain boundaries.
Uses & applications
Used as decorative stone, crushed stone for construction, road ballast, and occasionally as lapidary material for tumbling or carving.
Geological facts
Quartzite is so tough that it often outlasts the surrounding rocks during erosion, often forming the tops of ridges and mountains. It is harder than a steel knife and will easily scratch glass.
Field identification & locations
Identify by its extreme hardness and the way it breaks through quartz grains rather than around them (unlike sandstone). Commonly found in abrasive environments like riverbeds or ancient mountain ranges.
More like this
