Dunks,
Thank you for the information. However, I researched it a bit this morning, and there is no doubt in my mind that your horn is a snuff container from Africa.
Here is a "snuffbox" collected from the Maasai:
The container is shaped differently, but look at the chain. It is virtually identical to the chain in the photo in the original post. Maybe chain of this type was an item of trade.
I don't know the tribal association from the next one... Just that it came from somewhere in the Dark Continent:
This next on came from the Kamba people of Kenya:
Compare the metal dot inlays to those in the original post. The metal inlay on all of these horns, incidentally, was identified as aluminum.
I first read John Hunter's book
African Hunter (over and over...) when I was nine years old. I recall one passage in which Hunter shot a rhino or elephant with one of those massive African cartridges. I think the kill required additional shots. He mentioned that his native tracker picked up the ejected brass cartridge cases to use in making snuff boxes. With that in mind, check this out, taking note of the brass neck on the horn:
You have a very interesting artifact in your hands, my friend. It may not be what we first thought, but I'm sure it has stories of its own to tell.
Best regards,
Notchy Bob