gems, garnet, rhodolite, Macon County, North Carolina, associated minerals

A coarse gneissic rock, which occurs on Masons Mountain, Macon County, North Carolina, and consisted originally of rhodolite and hypersthene, was partly transformed, by metasomatism, into anthophyllite-biotite gneiss. Later solutions, which developed quartz and sillimanite with minor rutile and graphite, accompanied pegmatites that contain quartz, feldspar, biotite, kyanite, staurolite, muscovite, and graphite. Both kyanite and staurolite are apparently pyrogenic in origin. The mineralization appears to have been localized along a fault.