igneous
Basalt
Basalt (Mafic Igneous Rock)
Hardness: 6 on Mohs scale; Color: Dark grey to black; Luster: Dull to sub-vitreous; Texture: Fine-grained (aphanitic); Specific Gravity: 2.8 - 3.0
- Hardness
- 6 on Mohs scale
- Color
- Dark grey to black
- Luster
- Dull to sub-vitreous
Identified More igneous →
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Physical properties
Hardness: 6 on Mohs scale; Color: Dark grey to black; Luster: Dull to sub-vitreous; Texture: Fine-grained (aphanitic); 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 a terrestrial planet or moon.
Uses & applications
Extensively used in construction as crushed aggregate, road base, concrete reinforcement, and for stone carving or architectural tiling.
Geological facts
Basalt is the most common rock type in the Earth's crust, forming the bulk of the oceanic crust as well as the lunar maria on the Moon.
Field identification & locations
Identified by its dark color, heavy density, and fine-grained matrix without visible large quartz crystals. Commonly found in volcanic fields, oceanic islands, and flood basalt provinces.
