by Owain Bury

Created on: August 06, 2007   Last Updated: July 18, 2010

Ever wanted some quick and easy chemistry experiments to try that can be done in your own home, with household items? Growing beautiful table salt crystals is an ideal starting experiment, will not take too long, and should fascinate the kids.

It is ideal because it is easy to obtain the salt and water, no special equipment is required and the crystals are non-toxic. Salt, otherwise known as sodium chloride, or halite, can be turned into fascinating shapes and designs with a few simple steps.

There are several methods around, but for this one, you will need

table salt - sodium chloride
water
clean, clear container X 2
piece of cardboard (optional)
string and pencil or butter knife (optional)

1) Boil the water on the hob and carefully pour into the clear container. Alternatively have it in a glass beaker and boil with a Bunsen burner, if doing it in class.
2) Stir table salt into the water and keep stirring so it dissolves quickly. Continue to add salt until the water is saturated and salt appears at the bottom of the container. Add and stir quickly so that the water remains near boiling whilst doing this.
3) If you want basic small crystals and fast, just soak a small piece of cardboard in the saturated salt solution. When it is soggy, remove and place on a plate before setting out to dry in a sunny area. Once dried, small crystals will form.
4) To create a larger, more impressive perfect cubic crystal you will need to make a SEED CRYSTAL
5) To do this, remove the unsaturated salt solution by pouring it carefully into a new clean container. Then dangle a piece of string attached to a small object like a pin or paperclip or pen lid into the container so that object is just off the base. Dangle it from a pencil rested across the top of the container.
6) Take the container carefully to a quiet, cool, shaded and undisturbed location where vibrations are avoided, like a cupboard and leave for a few days. Crystals will begin to precipitate on the dangled object in beautiful cylindrical formations.

A couple of tips regard the quest to make "perfect crystals." Using uniodized salt and distilled water will help make crystals that stack perfectly on top of previous crystals. Impurities in some salt and water can aid dislocation of crystals. Alternatively, DO vary the type of salt or water used, e.g. tap water or sea salt, to see what different shapes of formations arise.

Best of luck, and enjoy this simple but fun experiment!

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