How do I find the MAC address of a paired bluetooth device?

I have just connected a bluetooth device to my MacBook. When it was pairing, it displayed the MAC address of the device, but a few seconds later, the MAC address was replaced with a test description of the device. I need to figure out what that MAC address was.

For clarification, this is not an ethernet connection, it is Bluetooth. The device is a type of headset, it has no use accessable interface, and no the address is not on the device itself.

Thanks,

-- JC