n rare plagioclastic feldspar occurring in many igneous rocks
a dense dark grey fine-grained igneous rock that is composed chiefly of plagioclase feldspar and pyroxene
large mass of intrusive igneous rock believed to have solidified deep within the earth
An igneous rock of feldspathic composition, lamellar in structure, and clinking under the hammer
any of numerous minute rudimentary crystalline bodies of unknown composition found in glassy igneous rock
