igneous
Basalt (with possible epidote or olivine)
Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
Hardness: 6; Color: Dark grey to black with greenish/yellowish patches; Luster: Dull/Earthy; Structure: Fine-grained/Aphanitic; Specific Gravity: 2.8-3.0
- Hardness
- 6
- Color
- Dark grey to black with greenish/yellowish patches
- Luster
- Dull/Earthy
Identified More igneous →
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Physical properties
Hardness: 6; Color: Dark grey to black with greenish/yellowish patches; Luster: Dull/Earthy; Structure: Fine-grained/Aphanitic; Specific Gravity: 2.8-3.0
Formation & geological history
Formed from the rapid cooling of magnesium-rich and iron-rich lava at or very near the Earth's surface. The greenish tint suggests presence of olivine or secondary epidote alteration.
Uses & applications
Used widely in construction as aggregate, road base, and concrete; also used for stone carvings and high-durability floor tiles.
Geological facts
Basalt is the most common rock type in the Earth's crust and makes up most of the ocean floor. It is also found on the Moon and Mars.
Field identification & locations
Identify by its dark color, heavy weight (relative to size), and fine-grained texture. Found globally in volcanic regions like Hawaii, Iceland, and the Deccan Traps.
