Plato states that the innermost stone wall of the Atlantean seaport was made of "orichalch". The essential components of this intrusive igneous rock contains potassic feldspar quarts with biotite, pyrite, zircon, monazite, magnetite, tourmaline, and ilmenite. The appearance is rosy to dark red with bluish specks and can be found in marginal intrusions leading to magmatic depths. These granite rocks are highly prized as POLISHED BUILDING SLABS and are also used extensively in the extraction of RARE EARTH BEARING MINERALS.
