Growing Crystals
Ask Yourself: What are crystals? Where do we see them? Are they all the same shape?
What you will need:For clear crystals:
· Glass tumbler
· Hot tap water
· Spoon
· ½ cup washing soda
· magnifying glass
For Diamond crystals:
· alum powder (can be bought at a Chemist)
· hot water
· disposable cup
· glass jar
· thread
· a skewer or a pencil
What you do: For the clear crystals:
· Fill the cup up to about half way
· Pour the washing soda slowly into the water, stirring as you pour, until no more will dissolve.
· Set the cup aside and check the experiment often over the next few hours.
· Pour the washing soda crystals from the cup into a shallow disposable container.
· Place them in a warm, sunny place for 24 hours and let the water evaporate.
· Watch the crystals grow using your magnifying glass.
For Diamond crystals:
· Slowly pour the alum into the glass of water, stirring as you pour, until no more will dissolve. (you will be able to tell when you hear the grains scratching on the bottom of the glass and you can see some floating in the water)
· Keep the solution in the cup overnight. (You should be able to feel undissolved crystals)
· The next day, pour the water into the jar. Tie one end of the thread around a large piece of hardened alum crystal which you will find at the bottom or the side of the cup. Wind and tie the thread around the middle of a pencil and place the pencil over the jar so that the alum dangles low in the water.
· Watch the crystals grow over several days.
For both types of crystals: Use your magnifying glass, look at the shape of the crystals. Draw the different crystal shapes and compare them.
What you learned: Crystals are everywhere. Snow, sugar, salt, rocks and precious jewels such as diamonds are all crystals. They each have a different shape as different substances make different crystal shapes. Each different substance will always form the same crystal shape.