Basanite is a black basaltic rock which mainly contains plagioclase, augite, olivine and nepheline and is formerly used as a touchstone
Luxullianite is a rare type of granite, known for presence of clusters of radially arranged acicular tourmaline crystals which are enclosed by phenocrysts of orthoclase and quartz in a matrix of quartz, tourmaline, alkali feldspar, brown mica.
From Latin basanites + -ite
From the village of Luxulyan in Cornwall, England, where this variety of granite is found
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock