How to Grow Beautiful Crystals at Home with Your Kids

Learn simple, safe methods to grow stunning crystals at home using everyday household items your family probably already has.

1. What You'll Need. For salt crystals: table salt, hot water, string, pencil, glass jar, and food coloring (optional). For sugar crystals: granulated sugar, hot water, wooden skewer or string, clothespin, glass jar, and food coloring (optional). For Epsom salt crystals: Epsom salts (available at any pharmacy), hot water, glass jar, and food coloring (optional). You'll also want a measuring cup and spoon for mixing.
2. Growing Salt Crystals (Easiest Method). Heat 1 cup of water until it's very hot but not boiling. Slowly stir in salt, one tablespoon at a time, until no more salt will dissolve (you'll see undissolved salt sitting at the bottom). This creates a supersaturated solution. Tie one end of a string to a pencil and lower the other end into the solution. The pencil should rest across the jar's rim with the string hanging into the water. Place the jar in a quiet spot where it won't be disturbed. You'll start seeing tiny crystals forming within hours, with larger formations developing over several days.
3. Growing Sugar Crystals (Rock Candy). Heat 1 cup of water until almost boiling. Slowly add 2-3 cups of sugar, stirring constantly until completely dissolved. Let the solution cool for 30 minutes. Dip a wooden skewer in the solution, then roll it in granulated sugar to give crystals a place to start growing. Clip a clothespin to the top of the skewer and lower it into the solution, making sure it doesn't touch the bottom or sides. Cover the jar with a paper towel and secure with a rubber band. Place in a cool, undisturbed location. Crystal growth will be visible within a few days, with full rock candy forming in 1-2 weeks.
4. Growing Epsom Salt Crystals (Fastest Results). Heat 1/2 cup of water until very hot. Add Epsom salts one tablespoon at a time, stirring until no more will dissolve. Add 2-3 drops of food coloring if desired. Let the solution cool for 2-3 minutes, then place the jar in your refrigerator. Within 3-4 hours, you'll have beautiful needle-like crystals covering the bottom and sides of your jar. This method gives the quickest results and works well for impatient younger children.
5. What's Actually Happening. Crystal formation happens when dissolved particles in water arrange themselves in organized, repeating patterns as the water evaporates or cools. When you create a supersaturated solution (more dissolved material than water can normally hold), the extra particles need somewhere to go. They attach to your string or skewer and build up in geometric patterns, creating the beautiful crystal structures you see. Different materials create different crystal shapes because of how their molecules naturally fit together.
6. Making It Educational. Use this experiment to teach patience, observation skills, and basic chemistry concepts. Have children draw pictures of their crystals each day to document growth patterns. Measure crystal size with a ruler and create a growth chart. Compare how different materials create different crystal shapes and colors. Discuss why some crystals grow faster than others and how temperature affects the process. You can also explore how crystals form in nature by looking at rocks, gems, and minerals.