Yes, JIGSAW is a Scrabble word!

Letter values in Scrabble US: J 8, I 1, G 2, S 1, A 1, W 4.

Is it a valid word?

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

a portable power saw with a reciprocating blade; can be used with a variety of blades depending on the application and kind of cut; generally have a plate that rides on the surface that is being cut
fine-toothed power saw with a narrow blade; used to cut curved outlines

Also: saber saw, reciprocating saw, scroll saw.