This is realgar:
Well, that's the prettiest form of realgar, anyway. The stuff is formed round hot springs, and you can find it in Hungary, Germany, and the USA.
It's dangerous stuff. It's used to make "red explosive" for fireworks, especially torpedoes and crackling stars, and it's very poisonous (it's got a lot of arsenic in it). It's been used to kill rats, and in China it's been used as a snake repellent. It's still sometimes used as a weed and insect killer.
It's also used in Chinese medicine, and when mixed with rice liquor makes realgar wine, which is drunk during the Duanwu Festival to ward off evil. Well, that stuff would ward off anything. People are tending not to drink realgar wine so much, now, though, because of the whole made-of-arsenic thing.
Still, realgar has been jolly handy in its time. It's been used for removing the hairs from animal pelts, the Romans used it as a red pigment, and it's also been used in the manufacture of lead shot, in printing, and in dyeing calico.
But what's the best thing about it?
Well, its powerful and mysterious name is a big plus, but I'm afraid that as far as I'm concerned the very best thing about realgar is that, being made of arsenic and sulphur, its chemical formula is AsS.
Word To Use Today: realgar. This word comes from the Arabic rahj al-ġār, which means powder of the mine.