metamorphic
Quartzite Pebble
Quartzite (primarily SiO2)
Hardness: 7 (Mohs scale); Color: Light gray to white; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.6–2.7
- Hardness
- 7 (Mohs scale)
- Color
- Light gray to white
- 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 (Mohs scale); Color: Light gray to white; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.6–2.7
Formation & geological history
Formed from the metamorphism of quartz sandstone under intense heat and pressure. This specific specimen has been further shaped into a smooth pebble by fluvial (river) or coastal erosion processes.
Uses & applications
Used as decorative stone in landscaping, as an aggregate in construction, and occasionally in glassmaking or as a refractory material. Smooth pebbles are often used as 'worry stones' or for aquarium decor.
Geological facts
Quartzite is so hard that it will scratch glass and even high-quality steel. It is one of the most durable rocks on Earth's surface, resisting both physical and chemical weathering effectively.
Field identification & locations
Identify in the field by its extreme hardness and its sugary, granular texture when freshly broken. It can be found globally in mountain ranges and along beaches/riverbeds where metamorphic rocks outcrop.
More like this
