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Growing Crystals on Coal

Growing Crystals on Coal

(Note: if you are not an adult, please make sure you do this with adult supervision!)

What you need:

  • Coal, small lumps
  • ¼ Cup Water (distilled works best)
  • ¼ Cup Laundry Bluing
  • ¼ Cup Salt (non iodized)
  • 1 Tablespoon Ammonia
  • Glass dish

Mix water, salt, bluing, and ammonia together.   Place the coal in the dish and pour the mixture over the coal.

Be sure to NOT completely cover the coal with liquid, you want at least half of the coal out of the liquid. Place where it will not be disturbed, but will get air circulation.

After a day or two, you will see white crystals begin to grow on the coal.   Adding a few drops of food coloring will make colorful crystals.   You can add more salt and bluing after a few days to keep the crystals growing.

So what’s happening?

While there isn’t actually any chemical reaction occurring, the dissolved salt is recrystallizing, aided by capillary action in the coal and iron particles in the bluing.

Get in touch!

Share your results or pictures with us on Facebook. We'd love to see what you're able to create. Happy holidays!


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