What is "cyane"

In Roman mythology, Cyane or Kyane (Κυανῆ "dark blue" in Greek) was a nymph who tried to prevent Dis from abducting Proserpina, her playmate. Upon failure, she dissolved away in tears and melted into her pool. In a slightly different version, Cyane was the Naiad (i.e. the fresh-water nymph) of a spring in the Sicilian town of Syracuse. After witnessing Hades's abduction of the goddess Persephone and trying to prevent it, she was turned to liquid by Hades.

Cyane had as a partner the river god Anapos (or Anapis). She cited their love as an example of consensual relationship while trying to convince Hades not to take Persephone by force.