I LOVE this polish! It's so incredibly gorgeous layering over other colors. I bought it cheap on ebay and I would love to get a back up but it's so hard to find. If you see this one for cheap, definitely pick it up.
This is a weird color: it looks turquoise in the bottle, but when applied it's a semi transparent glittering shade: there's a very pale hint of sea aqua color and lots of silver and gold glitters. To achieve a bolder color you need several coats, but product is very litlle pigmented so that's not easy to get.
Product is expensive and I guess you could find lots of similar polishes for a fraction of the price, but application goes smooth like silk, and it's not messy like other nails products: final effect is very nice and polished.
Overall, I like it: you get a subtle effect, but I expected this to be different when I purchased it.
Turquoise Diablo is a paradox to me, because there are many similar glitter polishes for so much less $$$. That being said, it is unique in it's own way. There is very little pigmentation to the nail polish base itself, and it requires multiple coats to achieve a slight pearlescence. What appeals to me most about this polish is that the color is somehow unique, a very subtle sea green with very fine gold and green glitter. And it doesn't go on chunky like many glitter nail polishes, nor does it dry with a rough finish. All in all it is a lovely summer color and I am a bit addicted to it, but it does not have a high color payoff, so I would try before you buy.