metamorphic
Quartzite with Quartz Veining
Metamorphic Quartz Rock (SiO2)
Hardness: 7 on Mohs scale; Color: Gray, tan, and white; Luster: Vitreous to waxy when wet; Crystal Structure: Hexagonal (microcrystalline); Cleavage: None (conchoidal fracture)
- Hardness
- 7 on Mohs scale
- Color
- Gray, tan, and white
- Luster
- Vitreous to waxy when wet
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: Gray, tan, and white; Luster: Vitreous to waxy when wet; Crystal Structure: Hexagonal (microcrystalline); Cleavage: None (conchoidal fracture)
Formation & geological history
Formed from the metamorphism of quartz-rich sandstone under intense heat and pressure, often featuring secondary quartz veins that filled fractures via hydrothermal activity. Generally Proterozoic to Paleozoic in age.
Uses & applications
Commonly used as aggregate in road construction, as decorative landscaping stones, and occasionally for lapidary work in making polished 'river stones'.
Geological facts
Quartzite is so tough that it often outlasts the surrounding rocks during erosion, which is why it is frequently found as rounded cobbles in stream beds. The white lines are 'veins' created by silica-rich fluids.
Field identification & locations
Look for a rock that can scratch glass and shows a sugary or vitreous texture rather than individual sand grains. Commonly found in riverbeds and glacial deposits across North America and Europe.
More like this
