How to Grow Epsom Salt Crystals

Epsom salt crystals
Anne Helmenstine

You can find Epsom salts (magnesium sulfate) in the laundry and pharmacy sections of most stores. Epsom salt crystals are safe to handle, easy to grow and form quickly. You can grow clear crystals or add food coloring if you prefer. Here's what you need to know to make your own crystals.

Difficulty: Easy

Epsom Salt Crystal Materials

  • 1/4 cup Epsom salts (magnesium sulfate)
  • 1/2 cup water
  • shallow bowl or dish
  • sponge (optional)
  • food coloring (optional)

Here's How

  1. Boil the water in a microwave or on the stove.
  2. Remove the water from heat and add the Epsom salts. Stir the mixture until the salt is fully dissolved. If desired, add food coloring.
  3. If you have floating sediment (common if using impure Epsom salt), you can pour the liquid through a coffee filter to remove it. Use the liquid to grow the crystals and discard the coffee filter.
  4. Pour the mixture over a piece of sponge (optional) or into a shallow container. You need just enough liquid to cover the bottom of the container.
  5. For larger crystals, place the container in a warm or sunny location. Crystals will form as the water evaporates. For fast crystals (which will be smaller and delicate-looking), cool the liquid quickly by placing the container in the refrigerator. Cooling the crystals produces thin needles within half an hour.


  1. The sponge provides an extra surface area to allow the crystals to form more quickly and helps make them a bit easier to view and handle.
  2. Compare the appearance of the Epsom salts before stirring them into the water with the appearance of the crystals that are produced.
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Your Citation
Helmenstine, Anne Marie, Ph.D. "How to Grow Epsom Salt Crystals." ThoughtCo, Apr. 5, 2023, Helmenstine, Anne Marie, Ph.D. (2023, April 5). How to Grow Epsom Salt Crystals. Retrieved from Helmenstine, Anne Marie, Ph.D. "How to Grow Epsom Salt Crystals." ThoughtCo. (accessed June 9, 2023).