How to Get Crystals to Form on Coal
The technique of demonstrating how to get crystals to form on coal has fascinated children for years. A classic method involving mercurochrome and iodine can still be used if proper safety methods are observed. Crystals form because the porous material of the coal draws up the solution by capillary action. Then the liquid on the surface evaporates leaving solids behind to form the crystals. The crystals will continue to grow as long as more solution is added as it will pass through the coal and the formed crystals to deposit more solids on their surfaces.
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Things You'll Need
- Coal
- Hammer
- Distilled water
- Glass pie pan
- Glass jar
- Plastic measuring spoons
- Ammonia
- Iodine
- Non-iodized salt
- Mercurochrome
- Food Coloring
Instructions
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Getting Started
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1
Pound the coal with the hammer until each piece breaks into smaller-sized chunks. Spread the broken pieces of coal in the glass pie pan.
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2
Mix 2 tbsp. ammonia with 2 tbsp. distilled water and 2 tbsp. of non-iodized salt in a glass jar. Add 12 drops of mercurochrome to the solution.
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3
Pour the contents of the glass jar over the chunks of coal in the glass pie pan.
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4
Add 12 drops each of mercurochrome, iodine and food coloring randomly over the layers of coal.
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5
Set the pie pan in a place where it will not be disturbed and check for growth in two days.
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6
Add additional solution of 2 tbsps. each of ammonia, distilled water and mercurochrome if you want the crystals to grow larger.
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1
Tips & Warnings
Charcoal briquettes may be substituted if coal is not available. Small chunks of brick may also be used.
Iodine and mercurochrome are both toxic. Care should be taken when using and disposing of both.
