Yes, LODESTONE is a Scrabble word!

Letter values in Scrabble US: L 1, O 1, D 2, E 1, S 1, T 1, O 1, N 1, E 1.

Is it a valid word?

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

a permanent magnet consisting of magnetite that possess polarity and has the power to attract as well as to be attracted magnetically