igneous
Basalt with Quartz Veining
Basalt (Mafic Volcanic Rock)
Hardness: 6 (Mohs scale); Color: Dark grey to charcoal black with white quartz streaks; Luster: Dull/Earthy (matrix) to Vitreous (veins); Structure: Aphanitic (fine-grained); Specific Gravity: 2.8 - 3.0
- Hardness
- 6 (Mohs scale)
- Color
- Dark grey to charcoal black with white quartz streaks
- Luster
- Dull/Earthy (matrix) to Vitreous (veins)
Identified More igneous →
Explore Basalt with Quartz Veining 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 with white quartz streaks; Luster: Dull/Earthy (matrix) to Vitreous (veins); Structure: 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 near the surface of a terrestrial planet. The white veins are secondary hydrothermal quartz deposits filled in fractures.
Uses & applications
Commonly used as crushed stone for road base, concrete aggregate, railroad ballast, and occasionally for ground-layering in landscaping.
Geological facts
Basalt is the most common rock type on the Earth's surface and also covers large areas of the Moon, Mars, and Venus.
Field identification & locations
Identify by its dark, dense, fine-grained texture and heavy feel relative to its size. Can be found in volcanic fields, ocean crust, and riverbeds as rounded pebbles. Look for characteristic 'scratches' which are white mineral veins.
