Porphyry

por′fir-i, n. a very hard, variegated rock, of a purple and white colour, used in sculpture ( porfido ro o antico ): an igneous rock having a ground-ma enclosing crystals of feldspar or quartz.— v.t. Por′phyrise , to cause to resemble porphyry: to make of a spotted appearance.— n. Por′phyrite , one of the crystalline igneous rocks, which consists principally of plagioclase.— adjs. Porphyrit′ic , Porphyrā′ceo us , resembling or consisting of porphyry.— n. Por′phyroid , a crystalline and schistose rock containing porphyritic crystals of feldspar. [Through Fr. and L. from Gr. porphyrites — porphyra , purple.]