Black flakes coming off buffalo skull?

[kingcobb]

I got this from a friend about 2 months back. Lately the black coating on it has been flaking off.

 

I am not sure what it is and was curious if I should remove it or do I need to stabilize it with something?

[Harry Pristis]

If you value a vertebrate fossil (I exclude shark teeth here) -- and you want it to last -- consolidate it with a plastic.

You cannot reliably judge by eye what will happen to the bone after 2 years, or 5 years, or 15 years in your drawer. Bones with which you could drive nails when first collected may split after years in your drawer. Teeth, when thoroughly dry, may split. These splits cannot be repaired to the original condition because of distortion to the bone or dentin or cementum.

This may happen to any bone, so, if you're going to keep the bone, play the probabilities. Consolidate! Impregnation with plastic will prevent many later headaches (I'm not telling you to soak your head in consolidant). I am saying that there is nothing more disheartening to open a drawer and to find a prize specimen tooth split in two.

Trust the decades of museum experience.

[Randyw]

Consolidate it! Once it’s started it will only get worse. I recommend paraloid.

[sharkdoctor]

I am curious about the source of the bone. It looks a lot like bones found in rivers. They frequently have a black film that adheres to the outside. If the bone is fossil, the black will continue to adhere once the bone is removed from the river. If the bone is modern, the black film will form on the bone, but will start to flake of as the bone dries. 

 

The flaking you show in the pictures looks exactly like the flaking on modern bones recovered from rivers. The exterior bone material is not stone (heavily mineralized), so it breaks up below the black film as it dries.

 

I prefer Butvar, but any penetrating resin should stop this process permanently. I would think you would want to submerge the bone in a thin mixture of the resin, versus brushing on the exterior.

[kingcobb]

Yes it was fished out of a river a  while back.

[kingcobb]

Thank ya'll for the info. I will look into how to consolidate it.

[Yoda]

19 hours ago, Harry Pristis said:

If you value a vertebrate fossil (I exclude shark teeth here) -- and you want it to last -- consolidate it with a plastic.

Would you include fish with that?

[Harry Pristis]

5 hours ago, Yoda said:

Would you include fish with that?

 

I don't prepare fish; but, when my Green River stingray started to "shed" fine debris, I sealed the fish surface with Butvar B-76.  I first consulted the quarry owner/preparator to make sure the acetone solution would not conflict with whatever was originally used to prepare the fossil.