a dark, fine-grained, usually extrusive igneous rock that is more basic than andesite, consisting chiefly of plagioclase feldspars and pyroxene: often found in vast sheets, it is the most common extrusive igneous rock
a kind of unglazed, black pottery designed by Josiah Wedgwood
Origin: earlier basaltes ; from Classical Latin a dark Ethiopian marble: term used by Pliny for basanites ; from Classical Greek basanitēs, species of slate used to test gold ; from basanos, touchstone, test (ult. ; from Egyptian bḫnw) plush -itēs, -ite
A hard, dense igneous rock that makes up much of the material in tectonic plates. The part of the Earth's crust beneath the oceans consists mainly of basalt whereas continental crust consists mainly of less dense rocks, such as granite. (See plate tectonics.)
A dark, fine-grained, igneous rock consisting mostly of plagioclase feldspar and pyroxene, and sometimes olivine. Basalt makes up most of the ocean floor and is the most common type of lava. It sometimes cools into characteristic hexagonal columns, as in the Giant's Causeway in Anterim, Northern Island. It is the fine-grained equivalent of gabbro.