magma

A mixture of molten silicate rock, crystals, and gas within the earth, which may be erupted as lava or cool in place to form igneous intrusions.

By the pathside, there are occasional large boulders that shown black crystals the size of a fingernail; these are pyroxene minerals that had time to crystallise out deep within the chamber of liquid rock – or magma – beneath the volcano.

A basic algebraic structure consisting of a set equipped with a single binary operation.

Any soft doughy mass.

The residuum after expressing the juice from fruits.