Opi's Black Spotted is a special effects nail polish that enjoyed a limited release in Sephora stores in France. Like crackle nail polish, it has its effect by selectively revealing the color underneath. But, instead of cracking, Black Spotted creates a bubble-like effect that almost reminds me of a disease.
Because of its unique appearance and limited release, people went ballistic, eager to get their hands on this fancy new polish. Ebay sellers who could get their hands on a bottle were retailing it for up to $100. (That's more expensive per ounce than printer ink!) At the time of this posting, there are still a few ebay sellers trying to charge $60-$70 for 0.5oz of this stuff.
|There are lots of beautiful pictures of Black Spotted manicures, but I especially like this one by Nailderella.|
You can read her full post here: http://nailderellanails.blogspot.com/2012/06/opi-black-spotted.html
Luckily, a blogger called Peek-a-Polish thought to upload the picture of the ingredients.
Ethyl acetate and butyl acetate are common solvents in nail polish. But heptane? Heptane? That's the third ingredient? That's very unconventional and almost certainly not coincidental.
The other odd thing that I saw on the ingredients list was water. Water is not commonly found in nail polish. Water molecules, with their two shared electron pairs, is in a bent formation and, thus, is polar.
In chemistry, a good rule of thumb is that "like dissolves like". This means, of course, that two unlike substances will not mix. A nonpolar substance, like heptane, and a polar substance, like water, will repel each other, leaving you with puddles of water left on your nail, which creates the effect you find in Opi's Black Spotted.
Putting It To the Test
To confirm my hypothesis, I decided to see if I could recreate the effect of Opi's Black Spotted. You should NOT try this at home for personal safety reasons.
|"Heptane, flammable, harmful"|
Next, I started my very un-methodological task of figuring out the correct ratio of polish to water to heptane.
Too much heptane gave me weird, unusable clumps.
|Over Sinful Colors Fusion Neon|