Yes, TOPAZES is a Scrabble word!

Letter values in Scrabble US: T 1, O 1, P 3, A 1, Z 10, E 1, S 1.

Is it a valid word?

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

a yellow quartz
a mineral (fluosilicate of aluminum) that occurs in crystals of various colors and is used as a gemstone
a light brown the color of topaz

Also: false topaz, common topaz.