Main Entry:

ba·salt

Pronunciation:

\bə-ˈsȯlt, ˈbā-ˌ\

Function:

noun

Etymology:

Latin basaltes, manuscript variant of basanites touchstone, from Greek basanitēs (lithos), from basanos touchstone, from Egyptian bḫnw

Date:

1601

: a dark gray to black dense to fine-grained igneous rock that consists of basic plagioclase, augite, and usually magnetite

— ba·sal·tic \bə-ˈsȯl-tik\ adjective