That's the way I got mine.
Either break off a piece or use a plastic knife underwater (sponges don't like to be exposed to air). Transfer it to your tank in a bag without any air.
When you get it to your own tank, I recommend piercing it with a plastic toothpick and then attaching it to a rock with rubber bands for 10-14 days to help get it encrusted where you want it in your tank.