SILK
The legend is that Lei-tzu was in her garden when she picked some cocoons from a mulberry tree, and accidentally dropped one into her tea. When she pulled it out, she found it unwound into one long filament.
Then her husband built on this discovery, and developed methods for domesticating the silkworm and producing silk thread from the filaments -- processes that the Chinese were able to keep secret from the rest of the world for more than 2,000 years, creating a monopoly on silk fabric production. This monopoly led to a lucrative trade in silk fabric.
But another woman helped to break the silk monopoly. About 400 C.E., another Chinese princess, on her way to be married to a prince in India, is said to have smuggled some mulberry seeds and silkworm eggs in her headdress, allowing silk production in her new homeland. She wanted, the legend says, to have silk fabric easily available in her new land. It was then only a few more centuries until the secrets had been revealed to Byzantium, and in another century, silk production began in France, Spain, and Italy.
For her discovery of the silk-making process, Lei-tzu is also sometimes called Si Ling-chi, or Lady of the Silkworm, and is often identified as a goddess of silk-making.