Ambergris is often described as one of the world's strangest natural occurrences. It is produced by sperm whales and has been used for centuries, but for many years its origin remained a mystery. It has been called the treasure of the sea and floating gold. Ambrein, an odorless alcohol, is extracted from ambergris and used to make a perfume's scent last longer. For hundreds of years, perfumers have categorized the quality of ambergris according to its color, with the finest perfumes made from pure white varieties. Black ambergris is the least valuable because it contains the least ambrein.

Source: Natural History Museum