So apparently there's this thing that only exists in China (SO not fair) called a "Luminous Pearl". Yes, "luminous". As in, glows in the dark. Or in fancy talk: "...wonders of the mineral world that shine in the dark without the help of ultraviolet light." Seriously though, this kind of Fluorite is so rare that western geology doesn't even recognize its existence, and the Chinese only discovered the first one in 1982.
2. Magic Ball
These pearls are legendary in China (they call them "Yemengzhu"), and people travel all over the country for the chance to touch one. According to myth, touching one of these freaks of nature will bring you great fortune and prosperity. Though I think that most of them really go to all that trouble just so they can say that they touched the world's biggest ball. The beaut in the picture is currently on display in China's Hainan province, in case you're interested in all that good luck.
3. So Frickin' Huge
This puppy weighs in at 6 tons, and measures 1.6 meters in diameter (5.25 feet across). But don't make the mistake of thinking the earth spat it out in that perfect spherical shape. It took 3 years to get it as smooth as a baby's behind, because The Green Giant's other superpower is a toughness comparable to diamonds. Don't. Mess. With. It.
4. So Pretty... So Expensive...
How much does a gem like this cost? Only 2.2 billion yuan (US$ 331 million). The perfect stone for an engagement ring!