Yes, PARTED is a Scrabble word!

Letter values in Scrabble US: P 3, A 1, R 1, T 1, E 1, D 2.

Is it a valid word?

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

having a margin incised almost to the base so as to create distinct divisions or lobes

Also: split up, break up, start out, set forth, set off, set out, take off.