igneous
Basalt Pebble
Basalt (Mafic Extrusive Igneous Rock)
Hardness: 6-7 on Mohs scale. Color: Dark gray to black, often with a microcrystalline matrix. Luster: Dull to metallic-subvitreous. Cleavage: None. Specific Gravity: ~2.8-3.0.
- Hardness
- 6-7 on Mohs scale
- Color
- Dark gray to black, often with a microcrystalline matrix
- Luster
- Dull to metallic-subvitreous
Identified More igneous →
Explore Basalt Pebble in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 on Mohs scale. Color: Dark gray to black, often with a microcrystalline matrix. Luster: Dull to metallic-subvitreous. Cleavage: None. Specific Gravity: ~2.8-3.0.
Formation & geological history
Formed from the rapid cooling of magnesium-rich and iron-rich lava exposed at or very near the surface of Earth or terrestrial planets.
Uses & applications
Used in construction aggregate, road base, crushed stone, dimension stone, and as natural river rock decor.
Geological facts
Basalt is the most common rock type in Earth's crust, forming virtually all oceanic crust, as well as vast flood basalt plateaus on land.
Field identification & locations
Identified by its fine-grained texture (aphanitic), dark color, and high density. Commonly found along riverbeds, beaches, and volcanic landscapes globally.
