Want an educational and fun science experiment for Valentine’s day? You are in luck! Everyone will have a ton of fun with this Valentine’s Day Borax Crystal Heart experiment! This project is perfect for kids of all ages and is a great way to teach them about the scientific process.

Borax Crystal Hearts for Valentine’s Day
Crystal growing is a great science experiment for kids and makes an excellent Valentine’s Day project. This borax crystal hearts activity will be fun to try with your little one and works well as a decoration. This easy science experiment is a great way to get kids excited about science, especially if you’re looking forward to trying something new this February 14th.
We love growing borax crystals in our house and no matter how many times we do it the kids are always excited to see how they turn out! We like to change up the geometric shapes we make and what better shape to make than a heart for Valentine’s Day!

Growing borax crystals is always a cool science experiment and watching the crystal formation is always fun to see. We make this crystal science project just about every holiday. We started with our basic Borax crystal recipe and then change the pipe cleaner into different shapes and make the borax solution different colors depending on the holiday we are having fun for.
The kids will love being able to grow their own borax crystals, mine always tell me that it is so much fun when we make our own crystals no matter how many times we have made them. While this crystal experiment is a ton of fun and easy it is a must that there is adult supervision as you are working with chemicals.
Borax Crystals Science Experiments
- Everything you need to know about growing borax crystals
- Borax Crystal Shamrocks for St. Patty’s Day
- Borax Crystal Candy Canes

Is Borax Safe to Use When Making Crystals?
Borax is often used in crystal-growing projects because it produces large, beautiful crystals relatively quickly. While borax is safe to use in this capacity, it can be harmful if ingested, so it’s important to supervise your child during this project and make sure they understand not to eat the crystals.
Whenever you are using borax with kids, you want to take safety precautions. First, wear gloves when handling the borax solution, as it can irritate your skin. Also, be sure to keep the borax solution out of reach of children and pets when not being supervised. It can be harmful if ingested.
What is the best Borax to use?
I prefer to use mule team borax but you can also use store brand borax.
How Long Will Borax Crystals Grow?
Valentine’s Day Borax Crystal Heart will grow relatively quickly, usually overnight. However, if you want larger crystals, you can allow them to grow for a few days. Borax crystals stop growing when they reach equilibrium, which means they are no longer able to absorb any more water. This typically happens in a few days.

Why Didn’t My Borax Crystals Work?
There are a few reasons why your Valentine’s Day Borax Crystal Heart might not have grown. The first is that the solution wasn’t saturated enough. This means there wasn’t enough borax in the water, so the crystals couldn’t grow. The second reason is that the temperature might have been too cold. Borax crystals need warm temperatures to grow, so if it was too cold, they won’t grow. Finally, the crystals might have reached equilibrium.
How Can I Make My Borax Crystals Grow Faster?
If you want your borax crystals to grow faster, you can try a few things. First, you can make sure the solution is saturated. This means there should be more borax in the water than can dissolve. Second, you can try heating up the solution. This will help the borax crystals grow faster. Finally, you can try stirring the solution. This will help the borax crystals to form faster.
How Do You Make Heart Shaped Borax Crystals?
In order to make the Valentine’s Day Borax Crystal Heart, you are growing the crystals on a pipe cleaner. By shaping the pipe cleaner into the shape of a heart, as the crystals form, they will form in a heart shape. This is a fun way to create a shape while making crystals.

Can I color my Borax solution?
Yes if you would like to make colored borax crystals you can add a few drops of food coloring to the borax solution before placing the pipe cleaner into the solution. This will made the borax rock crystals grow colored.
Tips for this Science experiment
Colored pipe cleaners. If you don’t have colored ones it is ok, you can use a white one. I just prefer to use pink or red because they are for Valentine’s Day.
Use enough water. It is important that there is enough water in the mason jar to fully submerge the pipe cleaner into the crystal solution with out it touching the bottom of the glass. If you are using a taller glass or a larger glass you may want to double the solution amount so that the pipe cleaner is fully submerged in the water and borax solution.

Growing Borax Crystals Supplies
- 2 cups Water
- 6 tablespoons Borax powder
- 1 Pink or Red Pipe Cleaner (Chenille Wire)
- piece of String (Thread)
- 5-inch or longer Wood Skewer, popsicle stick, craft stick or a plastic Straw
- Wide Mouth 12 ounce Glass Jar or mason jar
- Microwave
- Oven Mitts
- Spoon
How to Grow Valentine’s Day Borax Crystal Heart
Place room temperature water into the mason jar and microwave for 2-3 minutes or until the water just starts to boil.
Using oven mitts, carefully remove the jar from the microwave and add the borax.

Stir until the borax is completely dissolved.
Form the pipe cleaner into a heart small enough to fit easily within the opening of the mason jar without having to bend it.

Tie the string to the top of the heart, then tie the other end of the string to the center of the wood skewer or a popscile stick with enough length to allow the heart to be fully submerged in the borax and water solution without touching the bottom of the jar.

Once the string is tied firmly, slip the heart into the jar and use the skewer and place it across the top of the jar to hold the heart suspended in the liquid by resting the skewer across the opening of the jar. Be sure that the pipe cleaner does not touch the bottom of the container or jar you are using.
Place the jar in a location where it will not be disturbed and allow it to rest for 24 hours.
Gently lift the skewer to remove the heart and discard the borax mixture.
Place the heart on a clean, dry surface to dry and trim off the string. Then display the crystal-covered shape.
Valentine’s Day Crafts for Kids
- Valentine’s Day Bingo Game Printable
- Valentine’s Day Color by number
- Valentine’s Day Popsicle stick love bug
- Valentine’s Day Floam Slime
Valentine's Day Borax Crystal Heart

Looking for a fun and easy Valentine's Day activity? Look no further than Valentine's Day Borax Crystal Heart experiment! This project is perfect for kids of all ages and is a great way to teach them about the scientific process. Plus, it's just plain fun!
Materials
- 2 cups Water
- 6 tbsp Borax
- 1 Pink or Red Pipe Cleaner (Chenille Wire)
- String (Thread)
- 5-inch or longer Wood Skewer or Straw
Tools
- Wide Mouth Glass Jar
- Microwave
- Oven Mitts
- Spoon
Instructions
- Place room temperature water into the mason jar and microwave for 2-3 minutes or until the water just starts to boil.
- Using oven mitts, carefully remove the jar from the microwave and add the borax.
- Stir until the borax is completely dissolved.
- Form the pipe cleaner into a heart small enough to fit easily within the opening of the mason jar without having to bend it.
- Tie the string to the top of the heart, then tie the other end of the string to the center of the wood skewer or a popscile stick with enough length to allow the heart to be fully submerged in the borax and water solution without touching the bottom of the jar.
- Once the string is tied firmly, slip the heart into the jar and use the skewer and place it across the top of the jar to hold the heart suspended in the liquid by resting the skewer across the opening of the jar. Be sure that the pipe cleaner does not touch the bottom of the container or jar you are using.
- Place the jar in a location where it will not be disturbed and allow it to rest for 24 hours.
- Gently lift the skewer to remove the heart and discard the borax mixture.
- Place the heart on a clean, dry surface to dry and trim off the string. Then display the crystal-covered shape.