metamorphic
Quartzite (Beach Pebble)
Quartzite (Composition: SiO2)
Hardness: 7 on Mohs scale. Color: Off-white to yellowish-tan due to iron staining. Luster: Vitreous to waxy. Structure: Granular/crystalline texture (sugary surface). Specific Gravity: 2.6–2.7.
- Hardness
- 7 on Mohs scale
- Color
- Off-white to yellowish-tan due to iron staining
- Luster
- Vitreous to waxy
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: Off-white to yellowish-tan due to iron staining. Luster: Vitreous to waxy. Structure: Granular/crystalline texture (sugary surface). Specific Gravity: 2.6–2.7.
Formation & geological history
Formed through the metamorphism of quartz-rich sandstone under intense heat and pressure. The individual quartz grains recrystallize and fuse into a solid mass. Likely eroded from nearby tectonic outcrops and rounded by water transport over thousands of years.
Uses & applications
Used in construction as crushed stone or railway ballast. High-purity quartzite is used to produce glass and silicon metal. Smalled polished pieces are popular for landscaping and home decor.
Geological facts
Quartzite is so tough that it often outlasts the surrounding rock, forming prominent ridges and hills. Unlike sandstone, which breaks around its grains, quartzite breaks through its grains when fractured.
Field identification & locations
Identify in the field by its hardness (it will scratch glass) and its sugary, crystalline texture when held to the light. Commonly found in riverbeds, glacial tills, and beaches. Collectors value well-rounded, translucent pieces.
More like this
