Pitchblende is a material that has helped scientists isolate plutonium, radium, and helium. Its major component, however, is uranium. And uranium reacts with acid. Dramatically.

Pitchblende got its name centuries ago, when miners found black ore in the ground which had the color of pitch, but a density that made them suspect it was full of metal. In 1789, it yielded up its first element. Martin Klaproth discovered that, when exposed to nitric acid, pitchblende dissolves. Expose the resulting solution to sodium hydroxide and you get an entirely new element with entirely new properties. Klaproth called it uranium. Pitchblende was renamed uraninite when chemists discovered it is mostly uranium and oxygen.


In most uraninite ore there are traces of other elements, which have come out through the years. Uraninite was the first source of helium that was accessible to scientists. (Astronomers peering through spectroscopes had long seen helium on the sun, but couldn’t find it on Earth.) But despite its many components people have never really got over pouring nitric acid on it. Why? First, it’s a good way to separate out the uranium.

Second, it makes the mineral glow. Pitchblende and nitric acid combine to form uranyl nitrate, or (UO2(NO3)2), which is fluorescent. It’s also triboluminescent, and will glow when its chemical bonds are ripped apart, but few people try this because, just as a bonus, it’s flammable. Most scientists keep themselves to safe procedures. Like dropping acid on uranium.

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