Do you know ghouls from goblins and ghosts?
type of ornamental stone, late 14c., porfurie, from Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites, a purple semi-precious stone quarried near the Red Sea in Egypt, from Greek porphyrites (lithos) "the purple (stone)," from porphyra (n.) "purple, purple dye" (see purple). Spelling Latinized mid-15c. Now used generally for a type of igneous rock without regard to color. Porphyrios was an ancient proper name.
Neoplatonist Greek philosopher, important both as an editor and as a biographer of the philosopher Plotinus and for his commentary on Aristotle's Categories, which set the stage for medieval developments of logic and the problem of universals. Boethius' Latin translation of the introduction (Isagoge) became a standard medieval textbook.