igneous
Basalt (Vesicular)
Extrusive igneous rock with vesicular texture
Hardness: 6 on the Mohs scale. Color: Dark gray to black, often with white mineral infills (such as calcite or zeolite). Luster: Dull to sub-vitreous. Crystal structure: Aphanitic (fine-grained), often containing visible vesicles (gas cavities). Specific gravity: 2.7-3.0.
- Hardness
- 6 on the Mohs scale
- Luster
- Dull to sub-vitreous
Identified More igneous →
Explore Basalt (Vesicular) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6 on the Mohs scale. Color: Dark gray to black, often with white mineral infills (such as calcite or zeolite). Luster: Dull to sub-vitreous. Crystal structure: Aphanitic (fine-grained), often containing visible vesicles (gas cavities). Specific gravity: 2.7-3.0.
Formation & geological history
Formed from the rapid cooling of low-viscosity, magnesium- and iron-rich lava flows on the Earth's surface. Vesicles form when trapped volcanic gases escape as the lava solidifies. Can range in geological age from recent volcanic activity to billions of years old.
Uses & applications
Used in construction, aggregate for road building, production of rock wool insulation, and occasionally as decorative stone or in landscaping.
Geological facts
Basalt is the most common rock type in the Earth's crust, primarily making up the ocean floors and large volcanic provinces like the Columbia River Plateaus and the Deccan Traps. The white patches visible on this specimen are secondary mineral deposits (calcium carbonate or silica) filling old gas bubbles.
Field identification & locations
Easily identified in the field by its dark color, heavy weight relative to size, fine-grained matrix, and characteristic vesicular (sponge-like) holes. Found globally in volcanic regions.
