Ambergris
Ambergris was one of the most rare and expensive raw materials used in perfumery. It has long been a favorite perfume ingredient, though its source was a mystery for many years. The gray, waxy stone-like pebbles were found washed up on beaches, but it is now known that ambergris is a calculus produced by the Sperm Whale. Today, Ambrox and Ambranum are used as an alternative to Ambergris, mimicking its delicate, sweet, somewhat woody and extremely persistent fragrance.