Things You'll Need
Instructions
Find several good-sized geodes. You may discover them while digging for crystals, or you can purchase them at novelty shops and caving stores. Find a flat space outside and dig a small hole in the ground, just large enough to cradle one side of a geode. Lay a cloth over the hole; this will catch any broken crystal and prevent the geode from getting dirty.
Score the geode around its circumference by holding it firmly in one hand and digging the corner of the chisel into its surface. Drag the chisel through the crust all the way around the geode. Set the geode on the cloth, pressing gently to settle it in the hole. Make sure the geode is stable by trying to rock it back and forth. Adjust as necessary.
Place the flat edge of the chisel against the score mark and strike the end of the handle firmly with a mallet. Turn the geode slightly, place the chisel on the next section of the score mark, and strike the chisel again with the mallet. Continue this way along the entire score mark or until the geode breaks open.
Be patient. Depending on how thick the crust is, the geode may take some time to crack. Once it does, pry it open gently with your fingers, if you can, or slide the chisel between the halves and twist it gently to reveal the shining crystals.