metamorphic
Yellow Quartzite
Quartzite (SiO2)
Hardness: 7 on Mohs scale; Color: Yellowish-tan to light brown; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Specific Gravity: 2.6-2.7
- Hardness
- 7 on Mohs scale
- Color
- Yellowish-tan to light brown
- Luster
- Vitreous to dull
Identified More metamorphic →
Explore Yellow Quartzite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 on Mohs scale; Color: Yellowish-tan to light brown; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Specific Gravity: 2.6-2.7
Formation & geological history
Quartzite is a metamorphic rock formed when quartz-rich sandstone is subjected to high heat and pressure, causing the original quartz grains to recrystallize into a dense interlocking mosaic.
Uses & applications
Used in construction as crushed stone or decorative rock, in landscaping, and sometimes for high-silica industrial applications. Smooth river-worn pieces are often used in decorative garden beds.
Geological facts
Quartzite is typically much harder and more durable than the sandstone it originated from. Its color variation is caused by impurities such as iron oxides which produce the yellow or reddish hues.
Field identification & locations
Identify by its extreme hardness (cannot be scratched by a steel nail) and the fact that it breaks across the grains rather than around them. Common in riverbeds and mountainous glacial deposits.
