Yikes, Phil.
This may be a damper pad, but to be honest, I have never seen a poly damper pad. I have only replaced the older felt ones. It looks black- I thought the new poly ones in the 08 series were white, but I don't know what the hell else it could be. Is is black from being rubbed by the damper? In any case, the damper will wear away and the base could be damaged as well. I found an A608 in mint condition. It was tossed because the damper pads were totally gone and with each spin the damper and base were grinding away. I can only imagine the horrible noise during the spin. Anyway, it awaits a new damper and pads. The pads in my A612 are dry- it is important to keep them lubed. If you want, I will send you a copy of the service manual pages on how to lube or change the damper and pads. Is the thing loose or is it stuck under the damper?
Bobby in Boston