OK, thanks!
Don't know yet, waiting for Gary to respond. I am leaning towards Sapphires as I believe YAGs do not have the same variety in colours.
DK
Ah, okay. I'll probably get sapphires too then, since they are hardest and also maybe come in more colors. I am also waiting for a reply from Gary. He must be scratching his head, getting two requests for interchangeable stones at the same time.