igneous
Granite River Pebble
Granite (composed of Quartz, Feldspar, and Mica)
AI-generated identification · may be incorrectHardness: 6-7 Mohs; Color: Salt and pepper (gray, white, pink, black); Luster: Dull to phaneritic; Texture: Phaneritic (visible grains); Specific Gravity: 2.63-2.75
- Hardness
- 6-7 Mohs
- Color
- Salt and pepper (gray, white, pink, black)
- Luster
- Dull to phaneritic
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Physical properties
Hardness: 6-7 Mohs; Color: Salt and pepper (gray, white, pink, black); Luster: Dull to phaneritic; Texture: Phaneritic (visible grains); Specific Gravity: 2.63-2.75
Formation & geological history
Formed from the slow subterranean cooling of silica-rich magma (plutonic). This specific specimen has been rounded by mechanical erosion in water (fluvial transport).
Uses & applications
Used in construction, gravel, landscaping, and as architectural stone. In this pebble form, it is common in decorative garden beds or aquarium decor.
Geological facts
Granite makes up a large portion of the Earth's continental crust. It is often older than the oceanic crust, with some formations dating back billions of years.
Field identification & locations
Identified by its intergrown crystals of quartz (translucent) and feldspar (opaque white/pink). Found globally in riverbeds, glacial tills, and mountain outcrops. Look for the granular 'speckled' appearance.
