A hexagonal and trigonal mineral, native carbon 4(C) , polymorphous with chaoite, diamond, and lonsdaleite; scaly, soft, lustrous, metallic; greasy feel; as crystals, flakes, scales, laminae, or grains in veins or bedded masses or disseminations in carbonaceous metamorphic rocks; conducts electricity well, is soft and unctuous; immune to most acids; extremely refractory.