Thank you all for your input. I hope I become the wiser for it.
The reason for my post is that lately, there have been many sellers claiming the handles on their edged weapons being rhino horn. In some cases, these sellers are online, providing (sometimes blurry) photos.(How one can tell from photos, I don't know).
Normally, it wouldn't bother me what the handle material was, as I'm more interested in the blade.
However, in a couple of cases, during price negotiations, the seller kept citing 'rhino horn' as the reason for the 'high' asking price. Needless to say, not being an expert on rhino horn, I had to break off the negotiations. (A shame not being able to get a blade that I want, just because of a bit of rhino horn
Once again, thank you all.