metamorphic
Riverstone Quartzite (Iron-stained)
Quartzite (primarily SiO2 with Limonite/Goethite staining)
Hardness: 7 on Mohs scale; Color: Brownish-orange to tan due to iron oxidation; Luster: Dull to vitreous; Structure: Non-foliated granular; Cleavage: None (conchoidal fracture).
- Hardness
- 7 on Mohs scale
- Color
- Brownish-orange to tan due to iron oxidation
- Luster
- Dull to vitreous
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 on Mohs scale; Color: Brownish-orange to tan due to iron oxidation; Luster: Dull to vitreous; Structure: Non-foliated granular; Cleavage: None (conchoidal fracture).
Formation & geological history
Formed through the metamorphism of quartz-rich sandstone under intense heat and pressure. This specific specimen has been subsequentely weathered and smoothed by water action in a river or creek bed (alluvial deposit).
Uses & applications
Commonly used in construction aggregate, road ballast, and decorative landscaping. High-purity quartzite is used to produce glass and silicon metal.
Geological facts
Quartzite is so durable that it often outlasts the mountains it was formed in, becoming rounded cobbles that can travel hundreds of miles down river systems over millions of years.
Field identification & locations
Identify in the field by its inability to be scratched by a steel knife and its lack of reaction to acid. It is commonly found in glacial till, riverbeds, and beach deposits across North America and Europe.
More like this
