Porphyry is a very hard red or purple rock which was in the ancient world quarried only in Egypt and was reserved to the use of the
Pharaoh.
Porphyry (born about A.D.
233, died around
305) was born
Malchus in Syria, and was given his Greek name by his teacher
Longinus at Athens. Porphyry later became a follower of the
neo-Platonism of
Plotinus, of whom he wrote a biography. He was an opponent of
Christianity and wrote a book against it which has not survived. He wrote widely on religion and philosophy, including musical theory.
His most famous book is about Pythagoras, named Vita Pythagorae or Life of Pythagoras (which is not to be confused with the book with the same name by Iamblichus).