Yes, MAHOGANIES is a Scrabble word!

Letter values in Scrabble US: M 3, A 1, H 4, O 1, G 2, A 1, N 1, I 1, E 1, S 1.

Is it a valid word?

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

wood of any of various mahogany trees; much used for cabinetwork and furniture
any of various tropical timber trees of the family Meliaceae especially the genus Swietinia valued for their hard yellowish- to reddish-brown wood that is readily worked and takes a high polish
a shade of brown with a tinge of red

Also: mahogany tree, reddish brown, burnt sienna, venetian red.