Pink Star Diamond

Compressed carbon shouldn't be this valuable. But modern humans aren't exactly known for level-headed thinking when it comes to rocks this shiny. The Pink Star Diamond, which just sold at auction to a Chinese jeweler for $71.2 million, is now the world's most expensive gemstone. The 59-carat oval diamond is the largest internally flawless pink diamond ever graded, and took two years of cutting and polishing to become the fancy jewel you see here.