Will a hard rest on a blackberry curve also clear my contacts on my sim card?

What do you mean by a hard reset? Lately similar terminology is being used to describe different actions. If you mean simply pulling the battery out, and waiting 5-10 minutes before reinserting, no, your contacts won't be cleared. If you mean a reset via wiping the device, yes, your contacts will be cleared. You'd need to first back up the device before the wipe.