You can do a simple "magic" trick by making crystals appear in a glass of water, which are formed from substances dissolved in it. Do your own experiment with salt crystals and learn how it works at the same time.
Steps
Method 1 of 3: Simple Salt Crystals
Step 1. Heat a saucepan with water
You will only need a little water; a ½ cup (120 ml) will do. Heat it until bubbles start to form.
- Children must be under adult supervision when handling hot water.
- You will get better results with distilled water, but you can use potable water without problems.
Step 2. Choose the salt
There are many varieties of salt and each will form a different type of crystal. Do the test with the salts below:
- It will take a few days for common salt to form crystals. Iodized salt won't form crystals that easily, but it will still do the trick.
- Epsom salt (magnesium sulfate) forms smaller crystals, which are needle-shaped. However, these form faster than those from salt. You can buy Epsom salt at a drugstore.
- Alum forms crystals quickly, sometimes in just a few hours. You can find alum in the spice section of the grocery store.
Step 3. Add as much salt as you can to the saucepan with water
Remove the saucepan from the heat first, then add about ¼ to ½ cup (60 to 120 ml) of salt into the water, mixing very well, until the salt dissolves completely. If the water is completely clear and you don't see grains of salt anywhere, then add another tablespoon of salt. Keep doing this until you can't dissolve any more salt in the water.
- You just created a supersaturated solution. This means that the solution (the liquid) contains more salt than it can handle.
Step 4. Pour the water into a clean jar
Pour the hot water very carefully into a jar or other heat-resistant container that is clear. This container must be completely clean, to prevent residues from interfering with the formation of the crystals.
Pour in the water slowly and stop before the undissolved grains of salt fall into the jar. If these grains of salt fall into the jar, the crystals will grow around them instead of the string that you will place later
Step 5. Add food coloring (optional)
You can add a couple of drops of food coloring to change the color of your crystals. Although it will make them slightly smaller and have a slightly different texture, they will not change much.
Step 6. Tie a piece of string to a pencil
The pencil should be long enough to sit comfortably on top of the jar. You can also use a popsicle stick or some other thin stick.
The piece of string has very small channels and rough edges that will allow the salt to stick to it and crystals begin to form. A fishing line will not do you good, because it is too smooth
Step 7. Cut the string until you have a piece of the right size to hang inside the jar of water
Crystals will only form on the submerged part of the string. Make sure the string is short enough so it doesn't touch the bottom of the jar. Otherwise, your crystals will end up being too small.
Step 8. Rest the pencil on the glass jar
The string should hang inside the jar, until it is submerged in the water. If the pencil moves too much, tape it to the jar.
Avoid letting the string touch the sides of the jar. Your crystals will end up being smaller than normal
Step 9. Put the jar in a safe place
Keep the jar in a place where there are no animals or small children around. Here are some tips to help you choose a suitable location:
- To quickly form lots of crystals, place the jar in the sun and keep a fan nearby on the lowest setting. These crystals will not grow too large, staying quite small.
- To make a large crystal instead of smaller crystals clumped together, place the jar in a cool, dark place. Place the jar on a polystyrene pad or other similar material to absorb vibrations. Although there is a good chance that you will end up with stacked crystals rather than a larger crystal, these crystals will be larger than usual.
- Crystals made with Epsom salt (and other rare salts) will grow faster in the refrigerator instead of in the sun.
Step 10. Wait for the crystals to start to form
Check the jar regularly to see if salt crystals have formed on the string. Epsom salt and alum crystals typically form in just a few hours, but it may take a few days to do so. The common salt will take a few days and sometimes up to a week. When you start to see crystals on the string, they will generally start to grow and grow over the next several weeks.
When the water cools, it will contain more salt than it can normally handle. As this makes it too unstable, the dissolved salt will leave the water and catch on to the string with just a little push. Also, as the water evaporates, the salt stays behind, making it even more unstable and helping the crystal grow more easily
Method 2 of 3: Large Salt Crystal
Step 1. Make a cup of salt crystals
Follow the same instructions as before, but use distilled water, and forget the pencil and string. Just leave the salty water in the container. A layer of salt crystals will form in the next few days at the bottom of the container.
- Use a wide, shallow container instead of a jar. This will make it easier to form a single large crystal that has not joined others.
- Epsom salt will not work in this method. Alum or common salt is preferable, although you can see some variations below for other ideas.
Step 2. Choose a crystal that will serve as a "seed"
When the crystals are ready, pour the liquid out of the container and observe the crystals that have formed. Pick them up with tweezers and examine them very well. Next, choose a "seed crystal" that will form the core of your large crystal. Look for crystals that match the following description (from most to least important):
- A lonely crystal that is not in contact with others
- A glass with flat and uniform surfaces, whose edges are straight
- A large crystal (that is at least the size of a pea)
- Ideally, it is best to choose several crystals and place each one in a separate jar as described below. Many crystals do not grow or dissolve easily, so it is good to have a backup.
Step 3. Place a fishing line or smooth wire in the jar
Glue it to the side of the glass or tie it around the glass.
Don't use string or rough wire. Crystals need a smooth surface to grow on the larger crystal instead of the string
Step 4. Make another solution
Use distilled water and the same type of salt. This time, heat the water just a little bit, because it should be slightly above room temperature. The purpose of this process is to create a perfectly saturated solution. A low saturated solution will dissolve your crystal, while a supersaturated solution will coat your crystal with an amorphous mass of smaller crystals.
There are faster ways to solve this problem, although they are more complicated and you will need some knowledge of chemistry
Step 5. Place the crystal and the solution in a clean container
Clean a jar and rinse it very well with distilled water. Pour the solution into this jar and then hang the crystal in the center. Save it as described below:
- Place the jar in a cool, dark place, such as a relatively hidden sideboard.
- Place the container on a polystyrene pad or other material that absorbs vibrations.
- Place a coffee filter, a piece of paper, or a thin cloth over the jar to prevent dust from entering the jar. Do not close it hermetically.
Step 6. Check the jar regularly
The glass will grow more slowly, because the water will have to evaporate before the grains of salt can catch on to the glass. If everything works properly, the crystal will keep its shape as it grows. You can take it out of the container any time you want, but it will surely continue to grow for several weeks.
- Every two weeks, filter the solution (with the coffee filter) to remove impurities.
- Making a large crystal is a difficult process. Even experienced people have a crystal dissolving or turning into an amorphous mass. If you have a perfect seed crystal, it is recommended that you try this process on a lower quality crystal to confirm that the solution is working properly.
Step 7. Protect the finished glass with nail polish
When the glass is big enough, remove it from the solution and let it dry. Then cover it with clear nail polish to prevent it from wearing off over time.
Method 3 of 3: Variations
Step 1. Try to make crystals with different substances
There are many substances that will form crystals with the techniques listed above. You can buy these chemicals at a store that sells chemical supplies. These are some of your options:
- Copper sulfate to form blue crystals
- Chromium alum to form purple crystals
- Cupric acetate to form dark blue-green crystals
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Warning:
These chemicals are harmful to health when inhaled, ingested, or handled without gloves. Read the safety information on the label and do not allow children to come into contact with these substances without adult supervision.
Step 2. Make a snowflake
Make a star with pipe cleaners or wires. Then place this star in the salt solution and watch the crystals form all over its surface, ending with a sparkling snowflake made with salt.
Step 3. Make a crystal garden
Instead of making a single crystal, why not make several? Prepare the salt solution and pour it on some cut sponges or charcoal briquettes at the bottom of the container. Then add some vinegar and watch the crystals form overnight.
- Pour enough solution over the sponges, enough to saturate them, but not soak them in the salty water.
- If you want to make crystals in other colors, add a splash of food coloring to each sponge.