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How To Grow Table Salt or Sodium Chloride Crystals

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These are cubic crystals of table salt or sodium chloride.

These are cubic crystals of table salt or sodium chloride. The salt crystals were produced by evaporating a salt solution on a black plate. The crystals are 3-mm across.

Björn Appel
Table salt or sodium chloride crystals are great crystals to try if you've never grown crystals before because it's easy to find salt and water (the ingredients), the crystals are non-toxic, and no special equipment is required. Let's get started!
Difficulty: Easy
Time Required: a few hours to several days, depending on your method

Here's How:

  1. Stir salt into boiling hot water until no more salt will dissolve (crystals start to appear at the bottom of the container). Be sure the water is as close to boiling as possible. Hot tap water is not sufficient for making the solution.
  2. If you want crystals quickly, you can soak a piece of cardboard in this supersaturated salt solution. Once it is soggy, place it on a plate or pan and set it in a warm and sunny location to dry out. Numerous small salt crystals will form.
  3. If you are trying to form a larger, perfect cubic crystal, you will want to make a seed crystal.
  4. To grow a big crystal from a seed crystal, carefully pour the supersaturated salt solution into a clean container (so no undissolved salt gets in), allow the solution to cool, then hang the seed crystal in the solution from a pencil or knife placed across the top of the container. You could cover the container with a coffee filter if you like.
  5. Set the container in a location where it can remain undisturbed. You are more likely to get a perfect crystal instead of a mass of crystals if you allow the crystal to grow slowly (cooler temperature, shaded location) in a place free of vibrations.

Tips:

  1. Experiment with different types of table salt. Try iodized salt, uniodized salt, sea salt, or even salt substitutes. Try using different types of water, such as tap water compared with distilled water. See if there is any difference in the appearance of the crystals.
  2. If you are trying for the 'perfect crystal' use uniodized salt and distilled water. Impurities in either the salt or water can aid dislocation, where new crystals don't stack perfectly on top of previous crystals.

What You Need

  • table salt - sodium chloride
  • water
  • clean clear container
  • piece of cardboard (optional)
  • string and pencil or butter knife (optional)

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