Have you ever grown your own crystals at home? It’s an exciting science experiment that allows you to form beautiful, sparkling structures with just a few simple materials. One of the most popular and easy-to-grow options is borax crystals. With their shimmering square-shaped patterns, borax crystals are sure to dazzle both kids and adults.
But did you know that temperature plays a key role in how these crystals form and grow? In this beginner’s guide, we’ll look at the science behind borax crystals, and examine how warm versus cold temperatures impact their growth and appearance. You’ll learn foolproof methods for growing your own magnificent crystals at home. Let’s get started!
What Are Borax Crystals?
Borax, also known as sodium borate, is a naturally occurring mineral compound. It’s commonly used as a household cleaner and laundering booster. However, when borax is combined with water, it forms a supersaturated solution from which dazzling crystals can grow.
The water molecules help to dissolve the borax powder and provide the right conditions for crystallization. As the solution moves from a liquid state to a solid crystal form, the active borax molecules arrange themselves in repetitive patterns, clinging together ionically to form beautiful geometrical shapes.
Why Temperature Matters
Temperature plays a key role in borax crystal formation and growth. This is because solubility – how much borax powder can dissolve in the water – is directly affected by temperature.
Solubility Differences
- In warm temperatures, more borax powder can dissolve in the water, creating a supersaturated solution.
- In cold temperatures, less borax powder dissolves, meaning the solution has a lower saturation point.
As the solution cools and becomes more saturated, the excess borax molecules crystallize out of the solution. This allows crystal growth to occur.
So in warm temperatures, more borax can be dissolved to begin with, providing a higher concentration and faster crystallization when cooled. Meanwhile, a solution saturated in cold temperatures will have slower crystal growth because less borax initially dissolved.
Growing Your Own Borax Crystals
Growing borax crystals is an easy experiment that can be done by children and adults alike. Below are step-by-step instructions using the popular hot water method.
Materials Needed:
- 1-2 cups Borax powder
- Saucepan
- 4 cups water
- Measuring cup
- Mason jar or glass container
- Pipe cleaners, yarn, or pencil (for hanging crystals)
Step 1: Make Supersaturated Borax Solution
- Heat 4 cups of water in a saucepan until very warm but not boiling.
- Slowly stir in 1-2 cups borax powder a little at a time until no more dissolves.
- You want the water completely saturated with borax at the warmed temperature.
Step 2: Pour Solution into Container
- Carefully pour the warm supersaturated borax solution into your mason jar or glass container.
- Cover the container with plastic wrap or lid to prevent evaporation.
Step 3: Hang Pipe Cleaner or Yarn
- Tie a pipe cleaner, yarn, or pencil to a pencil or skewer laid across the top of the container.
- Ensure the pipe cleaner/yarn hangs down into the solution without touching the bottom.
Step 4: Allow Crystals to Grow
- Place the container in a warm area undisturbed for 24-48 hours.
- Crystals will begin to form on the suspended item as the solution cools and saturates.
- Larger crystals will grow the longer the solution is left undisturbed.
Crystal Shapes and Patterns
The ionic bonds that form between the active borax molecules result in crystals shaped like perfect squares. As the crystal continues to grow over hours or days, perfect squares begin layering on top of each other in grid-like patterns.
The basic square shape emerges because of the four positive and four negative poles present on the sodium borate ions. However, slight environmental changes can cause variations to the fundamental square crystals.
Common Borax Crystal Shapes
- Octahedron – eight-sided shape
- Dodecahedron- twelve-sided shape
- Hexagonal prisms
- Elongated rectangles
These variations add to the natural beauty and uniqueness of each crystal.
Impact of Temperature on Crystal Size and Growth
Now that we understand how crystals form, let’s examine how temperature affects crystal growth specifically.
Higher temperatures allow more borax to dissolve initially. This creates a supersaturated solution with a large concentration of active borax molecules available for crystal formation. As the solution cools, molecules rapidly come out of solution, causing rapid crystal growth.
In contrast, lower temperatures limit how much borax can dissolve. The cooled solution is less saturated, with fewer borax particles available for crystallization. This leads to slower crystal growth.
In summary:
- Warm temperatures = larger crystals & faster overall growth
- Cold temperatures = smaller crystals & slower overall growth
Here is a comparison of crystals grown in warm solution vs. cold:
| Crystal Attribute | Warm Solution | Cold Solution |
|---|---|---|
| Initial borax solubility | More borax dissolves | Less borax dissolves |
| Crystal size | Larger | Smaller |
| Growth rate | Faster | Slower |
| Crystal shape and pattern | Well-defined facets and sharp edges | Rounded edges and irregular facets |
To maximize crystal size and visibility of shapes/patterns, use warm solutions between 140°F to just below boiling temperature.
Fun Variations and Tips
Growing basic borax crystals is simple enough, but there are many fun ways to create unique crystal designs:
- Add food coloring or glitter – Drop a bit into your solution to tint crystals or make them sparkle.
- Use alum powder – Combine with borax powder for more defined octahedral shapes.
- Suspend objects – Hang flowers, spiders, pinecones, etc. with crystals forming on them.
- Microwave method – Dissolve borax in short bursts in the microwave, then cool to quickly form crystals.
Always use borax safely by wearing gloves and goggles, and keeping children supervised. With some borax, water, and creativity, you’ll be growing gorgeous crystals in no time!
Wrapping Up
I hope this beginner’s guide has shown that temperature plays a vital role in borax crystal formation and growth. While cold temperatures can produce crystals, warm solutions in the 140°F – 212°F range will dissolve more borax and result in large, beautifully faceted crystals.
Growing your own crystals is an inexpensive, engaging science experiment for both kids and adults. With simple ingredients like borax powder, water, and pipe cleaners, you can form dazzling crystals with square and octahedral shapes. Experiment with different temperatures and variations to discover the wonders of crystal growth firsthand.
Frequently Asked Questions
How do I make a supersaturated borax solution?
To make a supersaturated borax solution, heat 4 cups of water to very warm but not boiling. Slowly stir in 1-2 cups of borax powder until no more dissolves. The solution should be fully saturated with borax at the warmed temperature.
Do borax crystals grow faster in cold or warm temperatures?
Borax crystals grow faster in warm temperatures between 140°F – 212°F. The warm water allows more borax powder to fully dissolve, creating a highly concentrated solution. This provides abundant borax molecules for rapid crystal growth as the solution cools and saturates.
What shape are most borax crystals?
The most common borax crystal shape is a perfect square due to the ionic bonding of the sodium borate molecules. As crystals develop, they form stacked, grid-like patterns of squares. Under certain conditions, octahedral, hexagonal, and other shapes may also emerge.
How can I make unique borax crystals?
There are many ways to create unique borax crystals beyond the basic method:
- Add food coloring or glitter to tint crystals or make them sparkle.
- Combine borax with alum powder for more defined octahedral shapes.
- Suspend objects like flowers or spiders to grow crystals on them.
- Use the microwave method to quickly dissolve borax before cooling.
Is it safe to let kids make borax crystals?
Yes, growing borax crystals is generally safe for children with proper adult supervision. Ensure kids wear gloves and goggles when handling borax powder. Also, supervise the heating of water to avoid burns. Follow all safety instructions. With supervision, growing crystals makes for an exciting, educational science experiment.
How can I grow bigger borax crystals?
To maximize the size of your borax crystals, use warm temperatures between 140°F – 212°F when preparing the solution. This allows more borax powder to fully dissolve, creating a supersaturated solution. With more borax molecules available, larger crystals can form as the solution cools and saturates.
What causes crystal growth to slow down or stop?
Crystal growth may slow or stop if the solution becomes too cool or fully saturated. Agitating the solution can also disrupt crystallization. For continued growth, maintain warm temperatures and keep the solution undisturbed. Adding a fresh saturated borax solution to the existing crystals can spur further development.
How do I display my finished borax crystals?
Once your crystals are fully formed, use the pipe cleaner or yarn to gently remove them from the solution. Allow crystals to fully dry on a paper towel. Display them in glass jars, or glue them to cardboard for science fair projects. Ensure chemicals like borax are properly stored out of reach of children.
Can I grow borax crystals without pipe cleaners?
Yes, borax crystals will grow on the bottom and sides of a glass container filled with the saturated solution. Without pipe cleaners, crystals form as solid masses. The pipe cleaner allows formation of individual crystals that can be removed and displayed.