Black Sand Alchemical is a group of cobbin alchemists in Marielda. Its name comes from the black sand beaches of Emberboro, the unrecognized district of Marielda inhabited mainly by cobbins.
Relations
They began allying with the Black Slacks and the Weaver Union in "Four Conversations", forming an activist bloc.
Aubrey has a positive relationship with Black Sand Alchemical, although she is not a member. On her off days she has been known to visit their training centers (while pretending to be a fellow student) to advise them on their techniques.