You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For consistency, answers should be in all lower cased letters.

Category: STAGE NAMES 
Clue: Riley is the first name of this guitarist whose stage initials stand for "Blues Boy"
b.b. king

Category: "BLACK" MOVIES 
Clue: This 1979 Disney sci-fi film starring Maximilian Schell was nominated for an Oscar for Visual Effects
the black hole

Category: ROCKS & MINERALS 
Clue: A mixture containing antimony is sprayed on canvas to render it this

fireproof