Two tone diamond heart necklace

I recently won this piece on a Carnival cruise ship in a raffle (lucky me!) It comes from EFFY and Diamonds International located in sunny Aruba The chain is adjustable from 48-56cm The pendant is gold plated and has a 0.2 carat diamond embedded within. The jewlers on the ship appraised and sold these for $250 USD ($360 CAD) Unfortunately it did not come with paperwork to certify authenticity.