Purple

As part of a bible study I took a tangential look at purple.

In the New Testament there is mention of Lydia who was a seller in purple dye, obviously rich as she had a house big enough to hold Christian meetings.

Where did this wealth come from?

The Greek word for her occupation is porphuropolis from a compound of porphura (the purple fish, a species of shell fish or mussel ) and poleo (to barter, to sell)

This snail lives in the central and western parts of the Mediterranean Sea. It was known since ancient times as a source for purple dye and also as a popular food “Tyrian Purple,” the purple dye of the ancients mentioned in texts dating back to about 1600 B.C., was produced from the mucus of the hypobranchial gland of various species of marine mollusks, notably Murex. It took some 12,000 shellfish to extract 1.5 grams of the pure dye. One gram of pure purple dye was worth ten or twenty grams of gold.

Legend credits its discovery to Tyrian Herakles, or rather to his dog, whose mouth was stained purple from chewing on snails along the Levantine coast.
Tyrian Heracles and the nymph Tyrus were walking along the beach when Heracles' dog, who was accompanying them, devoured a murex snail and gained a beautiful purple color around its mouth.
Tyrus told Heracles she would never accept him as her lover until he gave her a robe of that same colour.
So Heracles gathered many murex shells, extracted the dye from them, and dyed the first garment of the colour later called Tyrian purple.
The murex shell appears on the very earliest Tyrian coins and then reappears again on coins in Imperial Roman times.
These marine snails still live along Tyre's shores deep among the rocks and sunken archeological remains.

According to Aristotle and Pliny the Elder, the snails were gathered at the beginning of autumn or winter and kept alive in basket-work containers until a huge quantity had been collected, as each shell only produced a single drop of dye.
Το extract the dye the smaller shells were crushed with stones; the larger ones were pierced and a tiny gland (known as the anthos or flower) was removed from the neck of the mollusc.
The milky fluid from this was put into brine, a little vinegar was added and it was left in the sun where the colour gradually changed from yellowish to a deep purplish red. It was then either diluted or concentrated further by boiling it down.

Dye extraction is no longer a viable commercial venture in this way, dyes are made by chemical means.