Last summer, the Sephora by OPI team released 6 "mermaid" shades. The collection consisted of 6 bottles of greys, turquoise and blues.
I got one of them, Mermaid to Order after hearing all the great feedback it got.
I'll be honest, I was a bit disappointed. I would describe this as a a metallic turquoise with shimmer. The color gorgeous but I don't like the metallic finish too too much, since 95% of the time, you can see brushstrokes. It wasn't that bad here, but I'm still not fully in love with this color. It's a bit sheer so this took me 3 coats.
These are still available on Sephora's website here.