
igneous
Vesicular Basalt (Scoria)
Basalt (Vesicular)
Hardness: 5-6 (Mohs); Color: Black, dark gray, or reddish-brown; Luster: Dull to sub-metallic; Crystal Structure: Aphanitic (fine-grained) with vesicles; Cleavage: None; Specific Gravity: 2.5-3.0
- Hardness
- 5-6 (Mohs)
- Color
- Black, dark gray, or reddish-brown
- Luster
- Dull to sub-metallic
Identified More igneous →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 5-6 (Mohs); Color: Black, dark gray, or reddish-brown; Luster: Dull to sub-metallic; Crystal Structure: Aphanitic (fine-grained) with vesicles; Cleavage: None; Specific Gravity: 2.5-3.0
Formation & geological history
Formed through the rapid cooling of magnesium-rich and iron-rich lava. The holes (vesicles) are created by gas bubbles trapped in the magma as it solidifies at or near the Earth's surface.
Uses & applications
Used in landscaping, road construction as aggregate, concrete production, and as abrasive polishing stones (scoria/lava rock).
Geological facts
Basalt is the most common rock on Earth's surface, making up most of the ocean floor. It is also extremely common on the Moon and Mars.
Field identification & locations
Identify in the field by its dark color, heavy weight (relative to size), and characteristic holes or pits. Commonly found in volcanic fields, island arcs, and mid-ocean ridges.