Liquid silver nail polish?

Looks like ChG OMG.

Revlon Silver Screen might also be worth taking a look at, but it's a lot deeper, greyer and less metallic in tone. It has a tendency to show brushstrokes, but it's good if you're going for the adamantium look.
 
Looks like Minx to me. I don't know if it's possible to get such a smooth shiny finish from the silver polishes - most of them are foils (like Zoya Trixie) or metallics (China Glaze Millenium). The closest Minx dupes I've seen are Stargazer Chrome 232 and Maybelline Mirror Magic. Here's a quick comparison on Nihrida's blog.