Noun
fishscale (plural fishscales)
(slang, idiomatic) Cocaine, usually of high quality taken directly off the brick and uncut.
When Doom anonymously submitted a beat tape for Ghostface Killah, several of his tracks made the cut for Ghostface's 2006 albums Fishscale and More Fish, including the song "9 Milli Bros.," which featured the Wu-Tang Clan in its entirety. Source: Internet