Murex Shell art in Black & White graphite on Canvas in a natural wood Bijou Frame.

The gastropods that live in these Murex shells  are commonly known as"rock snails". Their shells are highly sculpted with spines, and their inner surfaces often have bright colors. Tyrian purple is a pigment made from the mucus of Murex snails, which was produced in 1200 BC by the Phoenicians. This dye featured prominently in the clothing of high priests of ancient temples in Jerusalem; it's still used by some Jews even today for rituals.  

The color became associated with power and wealth, because it also took up an extensive amount of time to produce. The dye was greatly prized in antiquity because the color did not easily fade, but instead became brighter with weathering and sunlight.  Because it was extremely difficult to make, Tyrian purple was expensive: Purple for dyes fetched its weight in silver. The expense meant that purple-dyed textiles became status symbols, whose use was restricted by laws. The most senior Roman magistrates wore a toga with a stripe of Tyrian purple. The even more luxurious toga were solid Tyrian purple with a gold stripe, was worn by generals celebrating a Roman triumph. By the fourth century CE, laws in Rome had been tightened so much that only the Roman emperor was permitted to wear Tyrian purple.