Crystals

Crystals
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What did you think of your crystals? Weren't they cool? Had you ever heard of alum before? Technically speaking, alum is a hydrated double salt made of two metals, two sulfates, and water. Alum is used in dyeing cloth as a mordant. A mordant is a substance that sets the dye so it doesn't wash out. Alum is also used in water purification, making paper, fireproofing fabrics, making pickles, and in styptic pencils that stop shaving cuts from bleeding. Because alum is used in pickle making, you can find it in the spice section of your grocery store.

Here are two more great things to do with crystals:

Sugar Crystals
Sugar crystals can be a little trickier. Follow the same instructions but this time get a grown-up to help you heat the water on the stove. To get good crystals, you need to dissolve about 9 tablespoons of sugar in one half cup of water. That's A LOT of sugar. Make the crystals just the same except this time, before you put the yarn or string into the cup, wet it with water and then sprinkle some sugar on the yarn or string.

You could even try making fancy sugar crystal spoons by using a spoon instead. For best results, wet the spoon and sprinkle it with sugar before you put it in the cup.

Giant Crystals
This one takes a little work but is very cool. Kosher salt works best, but regular table salt will work as well. Once you have done this with salt, be sure to try it with other materials (try Epsom salts, alum, and sugar).

Make a super saturated solution with salt and water by having a grown-up heat about two cups of water on the stove. Add as much salt as you can. Pour the solution into a jar and let it cool. When some crystals have formed, strain the solution through a coffee filter or paper towel. Choose the largest crystal and put it back into the salt solution. Let it sit for several days to grow larger. Strain the solution into a saucepan. Take the large crystal and tie it on the end of a piece of thread. Heat the solution and add more salt. Strain the solution into a clean jar and suspend the crystal in the solution. To make the crystal larger, keep straining, heating, and adding more salt.