I think this is really cool. If you have the time its worth the watch. Just under 7 minutes long.

Meet Prince Rupert's Drop. It's about to blow your mind.

"Our guide is Destin from Smarter Every Day. If you aren't familiar with Destin or his YouTube channel, do yourself a favor and check it out. It is, consistently, some of the best informational science content out there today. That being said, this might be our favorite SED video ever. In it, Destin explores the bizarre and breathtaking properties of Prince Rupert's Drop, a teardrop-shaped glob of glass that is at once remarkably strong and explosively fragile. With the help of a camera with an obscenely high framerate (over 100,000 fps), Destin delivers the most lucid and entertaining explanation of the Drop's contradictory properties that we've ever had the pleasure of receiving."