Today I bring to you, not so much dupes, but more like two very similiar colors, Zoya Jem and OPI Diva of Geneva. Both are from last fall's collections, Smoke and Mirrors and Swiss, respectively. Now, in my bottle shot pic, they don't look all that similiar, but trust me, they are.
Both are a red violet with a bit of golden shimmer. In the bottle, it's more noticeable in Jem than Diva of Geneva, but you can still see it in Diva. Jem almost appears to be more foil like, where Diva is definitely a shimmer.
On the nail, you can really see the differences. I did two coats of each, no topcoat, Jem on index and ring fingers, Diva on the other two.
Jem is quite obviously the darker of the two, although the other similiarities are still there. Honestly, unless you're really into these kinds of reds, I would have to say you may not need both of them. Then again, I didn't either, but I just love reds :)