I've been pondering this one. So far I've not bee able to come up with a great idea for you. I do think to maybe give it some more time before you make a move.

questions: did you intend to just wear a diamond in one ear? that's fine if that's what you had in mind, just thinking this through. Maybe you could consider having your ear pierced in the upper cartilage for the diamond placement.

As someone above said, maybe consider having the ear pierced first and try another piece similar to what you have in mind before having the actual piece altered.

As an earring, I would recommend having the diamond set in a solitare setting with a locking (screw on) ear nut so that it would be secure.

It is a beautiful piece, but I am so much more into having things that you enjoy wearing.

I do think that you should still consider a necklace, that was my first thought. I wonder if the ring styling could be retained fairly intact and the diamond remounted so that it faced the side.