I also went with moissanite. My wife (then girlfriend) was in the "2-3 months salary for a diamond" camp which I find incredibly crass. Saved $15k on the diamond by going with moissanite and spent a fraction of that on getting a nice custom ring + wedding band made by an independent local jeweler instead. I was happy to support a local craftsman rather than DeBeers & co.
Yeah I told her exactly what it was when I gave it to her. We had had several discussions prior about my feelings about the diamond industry and the surrounding social expectations, so she knew I wasn't going to get her a diamond.
If she thought I gave her an expensive diamond and then learned from a jeweler that it was in fact a moissanite I would expect her to be upset about me misleading her.
2-3 months of salary for me would be a substantial contribution towards a deposit for a flat.My fiancé would smack my face if I'd spend it on a shining rock )
I was upfront with her about my dislike for the diamond industry and my feelings about spending 3 months salary on a diamond. I told her that I wasn't getting her a diamond and told her exactly what it was when I gave it to her.
I don't think I changed her perspective necessarily, but she knows what she got and respected my reasons for that decision. She didn't break up with me over it anyway.