Quasicrystals are a weird type of asymmetrical crystalline mineral that was only discovered a few decades ago, and it's only ever been produced in a laboratory under very carefully controlled conditions. At least, that's what we thought, until outer space chucked a meteor full of the stuff right at us.
Most crystals are made up of ordered and periodic structures of atoms. Ordered means that there's a pattern, and periodic means that the pattern repeats over and over again. A quasicrystal, however, is made up of patterns of atoms that don't repeat themselves, meaning that if you make a copy and shift it around you'll never be able to get it to line up with the original pattern.
For a long time quasicrystals were thought to be impossible, until a dude named Dan Shechtman got last year's Nobel Prize in chemistry for proving that they do actually exist. Here's an atomic model of what a quasicrystal pattern looks like:
We've been able to make quasicrystals in a lab by carefully depositing layers of metallic vapor in a vacuum chamber, and it was thought that the crystals were far too touchy to ever form by themselves in nature. However, a brand new mineral from outer space called Icosahedrite has all of these quasicrystal properties, despite being created 4.5 billion years ago out in space under conditions that one of the researchers describes as "completely nuts." In fact, we have no idea how this stuff was formed, we just know that it was, because we've found a piece of it inside a meteorite here on Earth. Kinda makes you wonder what else is out there, doesn't it?