This highly radioactive element is so rare that if every atom on earth were pooled together the resulting blob might be too small to see with the naked eye! And if you did see anything it would look like the tip of an arc welder's torch as the heat of all those atoms coming apart would be blinding indeed. The atomic structure of astatine is just too unstable for the metal to hold it together for more than a few hours at most.

With a particle accelerator making astatine is as easy as putting a chunk of sacrificial bismuth and flipping the on switch to fire alpha particles at it. Any alpha particle shooting by that happens to come close enough to the radius of the bismuth atoms will become bound through the strong nuclear force to form, briefly, this new element that immediately afterwards will start shaking like jello on a vibrator until its inevitable disintegration a few seconds or at most several hours later.