It’s Friday – what if…

… you wanted to create your own geode?  You could use an egg, some alum and some dye to do it.  With adult help, you can grow some beautiful crystals in just three days.

Materials –

  • a blown-out eggshell
  • alum powder (you can get this in the grocery store in the spice area)
  • white glue and a small paintbrush
  • dye, hot water and a plastic or glass container
  • a spoon for mixing, latex gloves (to keep your hands from getting dyed) and a place to dry your “geodes” the next day.

Steps –

  1.  Blow out a large egg.  Split it in half the long way by cracking and breaking it gently.  Wash and dry both pieces completely.  You can only grow one geode at a time but you can prepare both pieces with glue and alum powder at the same time.
  2. With the small paint brush cover the inside and cracked edges with white glue.  Sprinkle the glue with alum powder so it is completely covered.  Let it dry overnight.  (The crystals are going to grow on the alum, so coat the egg halves well.)
  3. The next day, prepare your growing solution.  You’ll need the container.  Put 2 cups of almost boiling water, 40 drops of food coloring and 3/4 cup of powered alum.  Mix the solution to be sure all the alum dissolves.  If there is any left in the bottom, place the solution in the microwave for a few minutes to dissolve them.
  4. Once the alum is completely dissolved, let the solution cool slightly (for about 30 minutes) and then submerge one of the dried, alum-coated eggshells in the growing solution.  allow it to rest on the bottom of the container with the inside of the shell facing up.

  5. Set the container in a safe place overnight to allow the crystals to grow undisturbed. The longer the eggshell is in the solution, the larger the crystals in the geode will be. 12 to 15 hours is just about right.

  6. When you’re ready, put the gloves on and remove the geode from the solution.  Be gentle, wet crystals are fragile.  Place your geode on newspaper to dry.  Let it dry completely before you handle it.
  7. If you’d like to make another geode, re-dissolve the crystals remaining at the bottom in the microwave and follow the directions again.  Have fun!