Yes, URANINITE is a Scrabble word!

Letter values in Scrabble US: U 1, R 1, A 1, N 1, I 1, N 1, I 1, T 1, E 1.

Is it a valid word?

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

a mineral consisting of uranium oxide and trace amounts of radium and thorium and polonium and lead and helium; uraninite in massive form is called pitchblende which is the chief uranium ore