rock formed by the solidification of molten magma

volcanic rock consisting of large fragments fused together

volcanic rock in which rounded cavities formed by expanding gas have subsequently become filled with mineral deposits

a grey volcanic rock containing plagioclase and quartz and other crystalline minerals

the commonest type of solidified lava; a dense dark grey fine-grained igneous rock that is composed chiefly of plagioclase feldspar and pyroxene

a kind of natural glass produced when molten lava cools very rapidly