metamorphic
Quartzite Pebble
Quartzite (SiO2 with minor impurities)
Hardness: 7 on Mohs scale (scratches glass); Color: milky white to light grey; Luster: vitreous to dull; Crystal structure: hexagonal/trigonal (microcrystalline); Specific gravity: 2.6-2.7.
- Hardness
- 7 on Mohs scale (scratches glass)
- Color
- milky white to light grey
- Luster
- vitreous to dull
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 on Mohs scale (scratches glass); Color: milky white to light grey; Luster: vitreous to dull; Crystal structure: hexagonal/trigonal (microcrystalline); Specific gravity: 2.6-2.7.
Formation & geological history
Formed from the metamorphism of quartz sandstone under intense heat and pressure. This specimen shows significant rounding and smoothing from fluvial (river) or coastal erosion processes.
Uses & applications
Commonly used as high-quality construction aggregate, glass manufacturing raw material, and as landscaping stones or 'river rocks' for decorative gardens.
Geological facts
Quartzite is so durable that it often becomes the 'caprock' on hills because it resists weathering better than the surrounding stone. It is often mistaken for white marble, but unlike marble, it will not react or fizz when touched by acid.
Field identification & locations
Identify in the field by its hardness (it should easily scratch steel or glass) and its granular, sugary texture when broken. It is a cosmopolitan rock found globally in ancient mountain belts and riverbeds.
More like this
