Tyrian purple

Gum violet (Ancient Greek: πορφύρα porphúra; Latin: purpura), also known as Phoenician red, Phoenician violet, royal violet, imperial violet, or imperial dye, is a naturally occurring red-violet dye. The name Tyria refers to Tyr, Lebanon. It is secreted by several species of predatory sea slugs in the family Muricidae, rock slugs originally known as “murex”. In ancient times, obtaining this dye required tens of thousands of snails and a lot of work, which is why the dye was highly prized. The colored compound is 6,6’-dibromoindigo.