Crystals are made up of atoms, molecules, or ions, arranged in highly ordered patterns with recognizable geometric structures. When you mix water with a crystal base, such as alum, salt, or sugar, you can watch the crystals form in a matter of hours. Learn how to make your own perfect crystals, create crystal ornaments, and make colorful rock crystal candies.
Steps
Method 1 of 3: Make crystals with alum

Step 1. Fill a jar halfway with warm water
Make sure the jar is clean, as you don't want other substances to interfere with your crystals. It is best to use a clear jar so that you can see the crystal formation process.

Step 2. Add some alum
Pour a few tablespoons of alum into the jar and use a spoon to stir the mixture until the alum dissolves. Add more alum and keep stirring. Keep doing this until no more alum dissolves in the water. Let the mixture rest for a few hours. As the water begins to evaporate, crystals will form at the bottom of the jar.
- Alum is a mineral used to pickle cucumbers and other vegetables, and it can be found in the spice aisle at your grocery store.
- You will know that you have reached the point where no more alum will dissolve when it begins to accumulate at the bottom of the jar.

Step 3. Extract a seed crystal
Choose the largest, best-looking, newly formed crystal to extract. Then pour the liquid from the jar into a clean one (try not to fill the clean jar with undissolved aluminum) and use a pair of tweezers to reach the bottom of the jar and remove the glass from the bottom.
- If the crystals are still very small, wait a few hours before extracting a seed crystal.
- If you prefer to continue making the crystals in the first jar, let them rest for about a week. At that point, the bottom and sides of the jars should be covered in crystals.

Step 4. Tie a string around the crystal and hang it in the second jar
Use a fine nylon thread or a piece of dental floss. Secure it around the glass, then secure the other end around a pencil. Place the pencil on the rim of the second bottle and suspend the glass over the solution.

Step 5. Wait a week for the crystal to grow
When the glass has reached the size and shape you want, remove it from the water. Untie the thread and enjoy the crystal you have made.
Method 2 of 3: Create Crystal Ornaments

Step 1. Make a water solution with alum
Fill a jar with water halfway, then dissolve several tablespoons of alum in the water. Keep adding alum until it no longer dissolves.
- You can also use salt or borax instead of alum.
- If you want to make ornaments in different colors, divide the solution into more than one jar.

Step 2. Add food coloring to the jar
Add a few drops of red, blue, yellow, green, or whatever color you like to the solution in the bottle. If you separated several bottles of solution, add different colored drops to each bottle.
- Mix drops of different colors of food coloring to make a unique color. For example, combine 4 drops of yellow with 1 drop of blue to make a pale green color, or mix red and blue to make purple.
- For festive decorations, make the decorations in colors that match your decorations.

Step 3. Fold pipe cleaners into ornaments
Give them the shape of trees, stars, snowflakes, pumpkins, or whatever else you want to give them. Make the shapes clear and easy to recognize, keeping in mind that the pipe cleaners will be covered with crystals, so the shapes will be thicker.

Step 4. Tie the pipe cleaners over the rim of the jar
Dip the shaped part of each of these into the jar, so that the shape is suspended in the center of the jar, without touching the sides or bottom. Pin the other side of the pipe cleaner over the rim of the jar, bending it slightly to keep it in place.
- If you have jars with more than one color solution, choose those that match the shapes you created with the pipe cleaner. For example, if you made a tree out of one, you can suspend it in a jar of green solution.
- If you suspend more than one pipe cleaner in the same jar, don't let them touch each other.

Step 5. Wait for the crystals to form
Let the pipe cleaners sit in the jar, or jars, for a week or two, until you like the size of the crystals. When you are satisfied with their appearance, remove your new glass ornaments from the jars. Pat them dry with paper towels. The ornaments are now ready to hang.
Method 3 of 3: Make Rock Crystal Candy

Step 1. Make a sugar water solution
To make rock crystal fudge, use sugar as your crystal base instead of alum or salt. Fill a jar halfway with warm water and stir in as much sugar as you can until it dissolves.
- The most common type of sugar to use is plain white, but you can experiment with brown sugar, raw sugar, and other types.
- Don't use artificial sweeteners instead of sugar.

Step 2. Add color and flavor
Make your rock candy more palatable by adding a few drops of food coloring and flavoring to the solution. Try these flavor and color combinations, or create your own:
- Red food coloring with cinnamon flavoring.
- Yellow food coloring with lemon flavoring.
- Green food coloring with mint flavoring.
- Blue food coloring with raspberry flavoring.

Step 3. Suspend wooden sticks in the solution
Put a few wooden sticks in the jar and angle their ends against the rim. If you don't have wooden sticks you can use wooden skewers or popsicle sticks.

Step 4. Cover the jar with wooden wrap
Since you are working with sugar, the solution could attract critters as the crystals form. Cover the jars with plastic wrap to prevent bugs from getting in.

Step 5. Wait for the crystals to form
After a week or two, the sticks will be covered in beautiful crystals. Remove them from the jar, let them dry, and then enjoy and share them with your friends.