Is this a real or fake rhino horn?

[-Andy-]

Hi all, I was recently gifted a lovely fossil from a friend. He told me it comes from a reliable digger from Sangiran and it is a rhino horn. However, I have my doubts

 

 

Rhino horns as I understand, are made of keratin which means they do not fossilize easily. Also, this fossil here is almost surely a bone. My friend tells me it is permineralized keratin but I am not sure if I agree with that. While there are indeed lines that flow from the base to the tip, I can't tell if they are carved or not

 

 

My friend mentioned this is a river find, hence the dark coloration. I rubbed it with acetone and revealed a different color underneath. I am 95% sure this is not wood however as there are no wood grains and the weight is more consistent with bone

 

 

What leads me to the conclusion that this is a real bone and not wood is the cross section. There is actual bone structure here

 

 

So, what is this "horn" exactly? My guess right now is that it is an actual bone (judging from the base) that was carved into the shape of a horn. There is a honeycomb pattern which you can see on the base. Traces of this pattern can be seen exposed by acetone. Perhaps most of the honeycomb surface pattern was destroyed by carving?

 

Anyway, I could be totally wrong. Maybe this is indeed a true fossil rhino horn and I am just over-paranoid. I would like your thoughts please, thank you

[JohnJ]

I would wipe down with acetone to reveal more detail.

 

The 'bottom' looks more like a mammal radius.

[Harry Pristis]

I would consider an ox radius as a possibility.  Here's a perissodactyl proximal radius:

 

[BellamyBlake]

Having been offered "rhino horns" from Indonesia, it's almost always carved bone. Horn doesn't easily fossilize, so it's probably not a rhino horn

[aplomado]

Do any of you see faint grind marks where the angle of the bone changes?  That is what I think I am seeing...  

[Harry Pristis]

It is an ox (or whatever the local large bovid is) radius.  It took skilled grinding to put the curve into it.

[JohnJ]

5 minutes ago, Harry Pristis said:

It is an ox (or whatever the local large bovid is) radius.  It took skilled grinding to put the curve into it.

 

Agreed.  Add some filler, stain and artistic groove/cracks....

[-Andy-]

I've been warned by a paleontologist once that Sangiran fossils are the riskiest in the world. Apparently, even museums can be fooled

 

Now it makes sense. Thanks for dissecting this bovine bone for me guys. I will keep it as a work of art

[LordTrilobite]

Yeah, absolutely not any type of horn. The surface structure it totally wrong. And the one end looks like a limb bone like the others already said.

[JorisVV]

Radius bone from a big mammal (likely wisent or gaur like), it is indeed filled, grinded and unnatural addings to make it look like a horn as @Harry Pristissaid