igneous
Basalt with Vesicle/Vug
Basalt (Aphanitic Mafic Igneous Rock)
Hardness: 6 (Mohs scale); Color: Dark grey to charcoal black; Luster: Dull/Earthly; Structure: Vesicular (containing small holes) or Aphanitic (fine-grained); Specific Gravity: 2.8 - 3.0
- Hardness
- 6 (Mohs scale)
- Color
- Dark grey to charcoal black
- Luster
- Dull/Earthly
Identified More igneous →
Explore Basalt with Vesicle/Vug in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6 (Mohs scale); Color: Dark grey to charcoal black; Luster: Dull/Earthly; Structure: Vesicular (containing small holes) or Aphanitic (fine-grained); 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 during volcanic eruptions. The holes (vesicles) are created by trapped gas bubbles escaping as the rock solidifies.
Uses & applications
Extensively used in construction, specifically as road base, concrete aggregate, and railroad ballast. Polished basalt is used for flagstone, floor tiles, and countertop surfaces.
Geological facts
Basalt is the most common rock on the Earth's surface; most of the ocean floor is composed of it. It is also found on the Moon and Mars, forming the dark 'Maria' seen from Earth.
Field identification & locations
Identify by its heavy weight (density), dark color, and fine grain where crystals cannot be seen by the naked eye. Often found in volcanic fields or as river rocks in volcanic regions.
