No there aren't. The majority of the people can't tell the difference between a man made diamond and a natural one. Most people can tell when they are in a super car instead of a Honda civic.
Moissanite has a slightly yellow color. Many diamonds do, but they are cheaper for it. It's essentially a K on the color scale of diamonds. It "shines" better but suspiciously so. I probably couldn't tell between a moissanite and a cheap diamond, but I could tell it's not a good diamond.
Lab diamonds aren't really cheaper than natural unless you are talking about pure shit quality or really tiny ones.
Lab diamonds aren't really cheaper than natural unless you are talking about pure shit quality or really tiny ones.