Do the magnet test - hold a magnet against the back of the case, and if it attracts, it's a tintype

As the others have said, though, not likely to be an Ambrotype at this late a date. Could be a tintype, put into an older case (in which case where is the photo that would have originally been in the case!

), but lack of reversal of the image pretty much rules that out. Also, there's what looks like a ring of deterioration on the photo where it meets the oval passepartout, which I would not expect to see on a tintype because of the binder used.
The case looks to be in poor condition, so it should be an easy enough matter to open up the image package and have a look inside to see what you have. Just be careful opening out the soft metal frame as it can split along the folds if you're not gentle with it.