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How to Color Alum Crystals

Making homemade crystals are excellent for science projects or crystal gardens because they are nontoxic, simple and safe to grow. You can purchase innumerable commercially-available kits for growing crystals. However, these kits can be very expensive. Fortunately, you can save a lot of money and make your own crystals using cheap ingredients you can find at your local supermarket. With a bit of time and effort, you can grow your own multicolored alum crystals at home.

Things You'll Need

Bowl
Alum powder
Baby food jars
Food coloring
Goggles
Gloves

Instructions

- 1
  Boil 4 cups of water in a microwave or on a stove top. Transfer the boiling water into a clean, dry, heat-proof bowl.
- 2
  Add 10 to 15 tbsp. of alum powder in the bowl and stir until dissolved. You can purchase alum powder at a supermarket in the spices section.
- 3
  Transfer the alum solution to clean baby food jars.
- 4
  Add 2 tbsp. of your favorite food color to each jar and stir.
- 5
  Cover the jars and leave them undisturbed for three to five days in a clean dry place. You will notice small and large clumps of colored crystals growing during this time.
- 6
  Remove the fully formed colored alum crystals and rinse them under running water. Make sure to wear gloves when handling the crystals so you don't get food coloring all over your hands. Examine the alum crystals or display them.

Rocks & Minerals