Tyrian purple

Tyrian purple, also known as royal purple, is a dye that was used as far back as 1600 BC. It was used by the Phoenicians, highly prized by the Romans, and was used to a lesser extent in the Middle Ages. It is thought to be the dye used in ancient times to make tzitzit, Jewish prayer shawls.

Tyrian purple is extracted from the murex, a marine snail. Pliny the Elder describes the production process in the 1st century AD.