A Diamond for Vandels

Weaponized Diamond Engagement Ring - Cory Doctorow @ BoingBoing

Now that is cool, but not surprising considering how hard a diamond is. But what I think people don't realize that if you hit a diamond in just the right way, you can shatter it. So while this might look cool, it's impractical and actually dangerous to the stone. There's a reason why the old European cuts have a dot in the center when you look at the stone from the very top; people were afraid of breaking that point, the culet, off.