metamorphic
Quartz River Pebble (Quartzite)
Metamorphic Quartzite (SiO2)
Hardness: 7 on Mohs scale; Color: yellowish-tan to light brown with mottled grey; Luster: vitreous to waxy when water-worn; Crystal structure: Macro-crystalline (heavily weathered); Cleavage: none; Specific gravity: 2.65.
- Hardness
- 7 on Mohs scale
- Color
- yellowish-tan to light brown with mottled grey
- Luster
- vitreous to waxy when water-worn
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: yellowish-tan to light brown with mottled grey; Luster: vitreous to waxy when water-worn; Crystal structure: Macro-crystalline (heavily weathered); Cleavage: none; Specific gravity: 2.65.
Formation & geological history
Formed from the metamorphism of quartz-rich sandstone under intense heat and pressure. This specific specimen has been rounded and smoothed by fluvial transportation over thousands of years in a river or stream environment.
Uses & applications
Commonly used as aggregate in construction, landscaping, and sometimes tumbled for decorative uses or aquarium gravel.
Geological facts
Quartz is the second most abundant mineral in Earth's continental crust. These smooth, rounded shapes are 'water-worn,' indicating a long journey from their original bedrock source through a drainage basin.
Field identification & locations
Identified by its high hardness (will scratch glass) and lack of foliation. Commonly found in riverbeds, glacial deposits, and beaches. For collectors, it is a basic staple of geological sediment studies.
More like this
