Noun: basalt bu'solt or 'ba,solt [N. Amer], 'ba,sólt or 'ba,solt or ba-sult [Brit]
- The commonest type of solidified lava; a dense dark grey fine-grained igneous rock composed chiefly of plagioclase feldspar and pyroxene
"The Giant's Causeway in Northern Ireland is formed of basalt columns"
Derived forms: basalts
Type of: volcanic rock
Encyclopedia: Basalt, Nevada