They often use ball lenses to collect light at the ends of optical fibers, so when you look stuff up on the internet you're actually scrying through a crystal ball.
After a pail of water was thrown on the Wicked Witch of the West outside Salt Lake City, Utah's Great Salt Lake was measured to be 7 parts per trillion witch by volume.
I have so many plans. It would incorporate a Galton board, a Ranque-Hilsch marble vortex tube, and a compartment lined with pinball bouncers with a camera-and-servo Maxwell's Demon that separated the balls into fast and slow sides.