porphyry
porphyry \'po.r-f(*-)re-\ n [ME porfurie, fr. ML porphyrium, alter. of L porphyrites, fr.] Gk porphyrite-s (lithos), lit., stone like purple, fr. porphyra purple 1: a rock consisting of feldspar crystals embedded in a compact dark red or purple groundmass 2: an igneous rock of porphyritic texture