a black bone key

This is a most strange piece of work. The key seems to be made from a fragment of bone, but where in the world does a creature have black bones? The skull of an unknown creature ornaments the key, its eyes two opaque worthless red stones. On your hand it feels cold, and no matter how long you hold it, the key never seems to warm up.

It is a black bone key.
It weighs half a pound.

You identify a black bone key.
It is an unsellable key.
It weighs seven ounces, and it is worth about fifteen busc.
Its keywords are key, black, bone, and bonekey.