metamorphic
Quartzite Pebble (Beach Pebble)
Quartzite (primarily SiO2)
Hardness: 7 (Mohs scale); Color: Tan, cream, or light brown with white internal veining; Luster: Vitreous to dull (waxy when water-worn); Structure: Granoblastic (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.7.
- Hardness
- 7 (Mohs scale)
- Color
- Tan, cream, or light brown with white internal veining
- Luster
- Vitreous to dull (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 (Mohs scale); Color: Tan, cream, or light brown with white internal veining; Luster: Vitreous to dull (waxy when water-worn); Structure: Granoblastic (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.7.
Formation & geological history
Formed from the regional or contact metamorphism of quartz-rich sandstone. High heat and pressure Recrystallized the sand grains into a dense, interlocking matrix of quartz crystals. This specific specimen has been further shaped and smoothed by high-energy beach environments (abrasion by waves and sand).
Uses & applications
Used in construction as crushed stone or road ballast; in industry for silica production; and in landscaping or as decorative 'river stones.' Highly smoothed pebbles like this are often used in jewelry (wire wrapping) or as 'worry stones.'
Geological facts
Quartzite is so durable that it often remains as pebbles/boulders long after the surrounding rock has weathered away. It is often harder than the steel blade of a knife, which is a key diagnostic test.
Field identification & locations
Identify in the field by its hardness (it should scratch glass) and its sugary, crystalline texture when broken. Commonly found on beaches, riverbeds, and in glacial till. Collectors look for unique colors or translucent properties.
More like this
