metamorphic
Quartzite with Hematite staining
Metamorphosed Quartz-rich sandstone (SiO2)
Hardness: 7 (Mohs scale); Color: Tan to yellow exterior with a reddish-brown iron-stained core; Luster: Vitreous to dull; Crystal structure: Hexagonal (microcrystalline); Cleavage: None, exhibits conchoidal or irregular fracture.
- Hardness
- 7 (Mohs scale)
- Luster
- Vitreous to dull
Identified More metamorphic →
Explore Quartzite with Hematite staining in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 (Mohs scale); Color: Tan to yellow exterior with a reddish-brown iron-stained core; Luster: Vitreous to dull; Crystal structure: Hexagonal (microcrystalline); Cleavage: None, exhibits conchoidal or irregular fracture.
Formation & geological history
Quartzite forms when quartz-rich sandstone is subjected to high heat and pressure, causing the sand grains to recrystallize and fuse together. The reddish color is due to the presence of Hematite (iron oxide) that has leached into the stone over geological time.
Uses & applications
Used in construction for road ballast, floor tiles, and stone walls. High-purity quartzite is used to produce glass and silicon metal. Small river-worn pieces are often collected by hobbyists.
Geological facts
Quartzite is so hard that it will scratch glass and even steel. It is often more resistant than the surrounding rock, which is why it frequently forms the peaks of hills and ridges.
Field identification & locations
Identify in the field by its extreme hardness and grainy texture that, unlike sandstone, breaks across the grains rather than around them. Often found in riverbeds as rounded 'cobbles' or 'pebbles' due to water erosion.
More like this
