Yes, GOLDFIELDS is a Scrabble word!

Letter values in Scrabble US: G 2, O 1, L 1, D 2, F 4, I 1, E 1, L 1, D 2, S 1.

Is it a valid word?

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

small slender woolly annual with very narrow opposite leaves and branches bearing solitary golden-yellow flower heads; southwestern Oregon to Baja California and Arizona; often cultivated
a district where gold is mined

Also: lasthenia chrysostoma.