Crack a Geode!
Geodes are are stone structures with an internal cavity lined with minerals. The mineral lining is often a druse of tiny quartz crystals underlain by multiple bands of translucent gray and white agate.
People who have never taken a geology course buy thousands of tons of geodes each year. They buy them because they enjoy cracking them open and surprising themseles with what they get!
Please note: All geodes may not containt the tiny icing like crystals.
Intructions: Wear safety googles. Set the geode in a sock or on the concrete on a newspaper, place the chisel in the middle, and tap it very gently a few times with the hammer. Turn the geode a quarter turn and do this again. Continue scoring along the circumference of the geode until you see a crack form all the way around, then pull the two halves apart.