What is a crystal ? A crystal is a beautiful, hard object with a very specific shape. It’s made of different things. Crystals can be as simple as sugar or salt crystals or as hard to find as diamond crystals. The shape of a crystal depends on what it is made of. In a salt crystal, tiny molecules (single pieces) of salt line themselves up into very neat rows, making a smooth shape. If you put a little bit of salt in water, the crystal will break up into single pieces and the single molecules of salt will be floating around in the water. If you let the water dry up, the same crystal shape will form again! Sugar does the same thing only its shape is different. If we put enough sugar in hot water and let it cool, we can make the sugar molecules line up again and form crystals in the water. It takes a day or so in order for the sugar to turn into a crystal again. If we do it right, we can make a much bigger crystal than we started with. salt crystals Salt Crystal looks like a cube Sugar crystal A few grains of salt A pint-sized jar A straight stick about six inches long Some string A microwave Water A magnifying glass (only if you have one) Sugar (about 2 1/2 cups) Let’s first look at salt crystals up close. If you have a magnifying glass, you’ll see them much better. Do they look anything like the picture? Try looking at sugar crystals. They are more complicated and don’t look anything like salt crystals up close. Now let’s make a bigger sugar crystal. Tie the string around the middle of the stick as shown in the picture. Make sure the string dangles into the jar almost all the way to the bottom. Take the string out of the jar. Pour about 1 cup of water into the jar. Have an adult microwave the water in the jar until the water is slowly boiling (about 2 minutes). Set the jar on a table and begin adding sugar, allowing it to disappear into the water. BE CAREFUL! THE JAR IS VERY HOT! Stop adding sugar if it seems like no more sugar is disappearing into the water. (If all the sugar dissolves, stop adding sugar after 2 1/2 cups have been added). Put the string back into the jar. Put the hot jar in a safe place and don’t handle it for at least one whole day. -------------------------------------------------------------------- -------------------------------------------------------------------- Crystals are cool, especially when you make them yourself! When you made sugar crystals, you needed hot water because more sugar will “dissolve” or disappear into the water when it’s hot. As the water cools, less sugar can dissolve into it and the crystal forms (much bigger this time) on the string. Sometimes, if you put too much sugar into the water, the whole thing turns into one huge crystal! The hardest crystal in the world is a diamond. Even if a crystal is big or small, it keeps the same shape. Some crystals can dissolve in water and some cannot. diamond Take the time to point out how uniform and “same” each salt crystal is. If you have jewelry with gemstones, show your child them and tell them that they are crystals, too, but instead of being natural, they were “cut” to a certain shape. The key to a crystalline solid is the uniformity of molecules and atoms. They line up in such a way as to be very smooth and of a shape that depends on the way the molecules interconnect to make up the crystal. More Kids Science Projects