Sea silk is a highly prized unique material made from Mediterranean clams. The only person who knows the ancient craft is an elderly Italian woman.
The Romans loved Chinese silk so much that the Senate banned its wearing by men in 14 A.D. It was hurting the economy as way too much silk was being imported and not enough of other stuff, like iron.
One million golden orb-weaver spiders lent their silk to create a shimmering, golden textile. Each spider had to be caught and “milked” by hand.