Russia announced Monday that it's been sitting on a huge deposit of diamonds buried under an impact crater in Siberia. And these aren't just any diamonds: they're twice as hard as normal, thanks to their instantaneously violent extraterrestrial origins.
The trillions of carats of diamonds (that's hundreds of thousands of tons) that are located underneath the Popigai crater in Siberia represent 10 times as much raw diamond as the entire world's supply of the diamond reserves all put together. Apparently, the Russians have known about the diamonds for about 40 years, but they've been happy to just keep it a secret and go on selling us all diamonds from other places in Russia instead.
It's no coincidence that this gigantic pile of diamond-laden rock is part of an ancient impact crater. The Popigai crater, which is the seventh largest impact crater on Earth at 62 miles in diameter, was formed about 35 million years ago when an asteroid somewhere between three and five miles in diameter smacked into Siberia. At this particular impact location, the ground had a bunch of graphite in it, which (like diamond) is a form of pure carbon, albeit a form that your fiancee will probably be slightly less thrilled to get from you.
Now, the old fashioned way to transform graphite (or other types of carbon) into diamonds is through the intense temperature and pressure that you find in some spots deep inside the Earth's mantle. This takes a long time and is boring. A more exciting way to make diamonds is to create the same temperatures and pressures via the explosive shockwave that you get when you crash an absurdly large rock into an even larger rock that's packed with carbon. In this case, as the shockwave passes through the ground, all of that carbon gets instantaneously transformed straight into diamonds.
Diamonds that are formed in this manner (called impact diamonds) retain some of the structural properties of the carbon from whence they came. In this case, that graphite structure makes the diamonds twice as hard as a "natural" diamond and unusually abrasive. You won't make jewelry out of impact diamonds, but they're ideal for industrial use in everything from cutting and polishing to making semiconductors.
Since diamonds like this don't exist in bulk anywhere else in the world, Russia is understandably somewhat excited on having a monopoly on enough impact diamonds to supply the rest of the world for (they estimate) the next 3,000 years or so. According to a Russian news agency, "use of these minerals in the manufacturing industry is capable of a technical revolution," but we'll have to wait and see what happens when these diamonds start getting pulled out of the ground by the fistful.