Basalt

3D Model

(Sample #4)

Rock Type: Igneous (extrusive/ volcanic)

Composition: feldspar, olivine, pyroxene, amphibole

Particle size: fine or mixed with no quartz

Hardness: 6 on the Mohs scale

Environment: Basalt is the solidified lava. However, it flows much quicker because it is less viscous. The Hawaiian Islands are made of Basaltic lava. The ocean floor is mostly basalt.

Distinguishing Characteristics: red-brown to black in colour. It can be tight grained or frothy with small visible hols where gas escaped while the lava cooled.

Uses: Basalt is crushed and used as crushed stone, concrete aggregate and railroad ballast. Basalt fibers are used in the production of high quality textile fibers, floor tiles, basalt plastic reinforcement bars, basalt fiber roofing felt and glass wool (fiber glass).