The rock bearing this name is so called from its purple colour. It is composed of a paste of red or reddish petrosilex, enclosing crystals of feldspar.

It was extensively employed by the ancients. The Egyptians worked it into statues, and it was later reserved more especially for seats, sarcophagi, and above all for ornamental vases. Its use was revived at the Renaissance, and Francesco Ferrucci, called "il Talda," distinguished himself in this laborious art-thanks, it is said, to the advice of Cosmo de' Medici, who taught him how to give his implements a higher temper. In the seventeenth century, porphyry was extensively employed for interior decoration.

The green variety of porphyry, known as verd-antique or serpentine, is an ophite with a hornblende compact feldspar base. The globulous porphyry of Corsica is the "pyromeride" of the French. Amongst the rarer kinds is black porphyry.