obsidian

noun

1. (uncountable, usually)A type of naturally occurring black glass produced by volcanoes.

   “The Neolithic culture from 8000 to 6000 B.C., however, was a brilliant period of the revival of crafts, the transformation of gathering into gardening, the growth of a cross-cultural obsidian trade, and the rise of towns.”

2. (uncountable, usually)A slightly bluish black, the color of obsidian glass.

adj

1. (poetic)Black.

   “Looks like a yellow biscuit of a buttery cue ball moon / Rolling maverick across an obsidian sky”