Make Colorful Crystals from Coal

3.6 based on 1074 ratings
Updated on May 6, 2014

Coal isn't just for Christmas stockings, old trains or grilling hamburgers. Here's an earth science fun fact: when coal is under great pressure for millions of years, it creates beautiful, sparkling diamonds. Your child won't have to wait nearly that long for their own pieces of coal to turn into gems. With a simple chemical experiment, she'll be able to create crystals before her very eyes!

What You Need:

  • 2 tablespoons table salt
  • 4 tablespoons liquid bluing
  • 2 tablespoons ammonia
  • Disposable plastic plate
  • Small glass jar
  • Disposable spoon
  • 8–10 charcoal briquettes
  • Food coloring

What You Do:

  1. Have your child mix a solution of table salt, liquid bluing and ammonia together in a small glass jar. Make sure she avoids breathing in the ammonia fumes.
  2. Stir the mixture with a spoon until the ingredients are well mixed.
  3. Ask her to place four charcoal briquettes onto the plastic plate and add a few drops of food coloring onto each piece of charcoal.
  4. Now, have her pour a small amount of the mixed solution on top of the charcoal.
  5. She'll notice that beautiful colors and shapes begin to emerge from the chemical reaction. While this process is unfolding, have her repeat steps 1–4 again for the next 4 pieces of charcoal.

This fun activity will not only introduce your child to geologic concepts, it will also help her to realize that beautiful things can come from unlikely places. Even the blackest briquette might be hiding a beautiful jewel!