metamorphic
Quartzite and Jasper Pebbles
Quartzite (re-crystallized Quartz) and Cryptocrystalline Quartz (SiO2)
Hardness: 6.5-7 (Mohs), Color: red, pink, brown, and grey, Luster: dull to vitreous, Crystal Structure: trigonal/hexagonal micro-textures, Specific Gravity: approx. 2.65
- Hardness
- 6
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 (Mohs), Color: red, pink, brown, and grey, Luster: dull to vitreous, Crystal Structure: trigonal/hexagonal micro-textures, Specific Gravity: approx. 2.65
Formation & geological history
Formed from the regional or contact metamorphism of quartz-rich sandstone. Most specimens in river gravels are aged between dozens to hundreds of millions of years old.
Uses & applications
Used for landscaping, decorative garden stones, tumbling, lapidary work, and as high-quality construction aggregate.
Geological facts
These pebbles are rounded due to fluvial erosion, meaning they were shaped by the movement of water over a long period. Many of the red hues come from trace inclusions of hematite.
Field identification & locations
Identify in the field by their extreme hardness (they will scratch glass) and lack of visible mineral grains. Commonly found in riverbeds, glacial tills, and shorelines worldwide.
More like this
