Most of those “rare earth” elements in the periodic table aren’t really that rare. Yttrium? Pshaw. You probably have some in your TV screen. Here are some of our favorite minerals that actually are uncommon.

Dienerite
A single piece was purportedly found in Austria in the 1920s. It has since vanished, and mineralogists debate whether it ever existed.

Armalcolite
These tiny gray crystals were named for astronauts Armstrong, Aldrin, and Collins, who collected them on the moon. A few samples have been mined on Earth.

Herbertsmithite
Found at just a few spots in the world, this unassuming greenish compound has weird electronic properties that could hold the key to quantum computing.

Wawayandaite
The only known sample, a bundle of winding white crystals, was discovered in New Jersey. They should have called it Fuhgeddabout-ite.

Bromellite
Or beryllium oxide. It’s nearly as hard as diamonds. Several gems have been cut from the one large sample found in Sri Lanka.

Tugtupite
The Inuit call it “reindeer blood.” Add sunlight and it turns from white to pink. Found in arctic regions—and crystal shops, where it’s sold as an aphrodisiac.