igneous
Granite Water-Worn Pebble
Intermediate to Felsic Phaneritic Igneous Rock
Mohs hardness: 6-7; Color: Mottled grey, white, and black; Luster: Dull/waxy (weathered); Structure: Holocrystalline/granular; Gravity: 2.6-2.7
- Hardness
- 6-7
- Color
- Mottled grey, white, and black
- Luster
- Dull/waxy (weathered)
Identified More igneous →
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Physical properties
Mohs hardness: 6-7; Color: Mottled grey, white, and black; Luster: Dull/waxy (weathered); Structure: Holocrystalline/granular; Gravity: 2.6-2.7
Formation & geological history
Formed from the slow cooling of magma deep underground, creating various mineral grains. This specific specimen was later tumbled and smoothed by water action in a river or beach environment.
Uses & applications
Commonly used in landscaping, as decorative garden stones, and sometimes in aquarium decor. In large scales, granite is a major construction material.
Geological facts
Granite is the primary rock type of the Earth's continental crust. These water-worn shapes are often called 'river rocks' and contain quartz, feldspar, and mica.
Field identification & locations
Identify by its speckled 'salt and pepper' appearance and hardness (it will scratch glass). Most commonly found in riverbeds, glacial tills, and along coastal areas.
