Yes, CHARCOALS is a Scrabble word!

Letter values in Scrabble US: C 3, H 4, A 1, R 1, C 3, O 1, A 1, L 1, S 1.

Is it a valid word?

CHARCOALS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a carbonaceous material obtained by heating wood or other organic matter in the absence of air
a stick of black carbon material used for drawing
a very dark grey color
a drawing made with a stick of black carbon material

Also: wood coal, charcoal grey, charcoal gray, oxford grey, oxford gray.