Supersaturated Borax Geode Crystallography Lab
A challenging, hands-on discovery and STEM project designed for curious young minds aged 10 to 14.
Materials Needed
- • Borax laundry powder (or pure Epsom salt) (1 cup)
- • Wide-mouth 1-quart glass mason jar (1 unit)
- • Chenille pipe cleaners (3 stems)
- • Boiling water (3 cups)
- • Cotton string and pencil (1 set)
- • Liquid food dye (1 small bottle)
Pro Tips
- → Stir borax into boiling water until powder visibly remains undissolved at the bottom; this guarantees complete thermal supersaturation.
- → Suspend the pipe cleaner shape so it hangs completely centered without touching the sides or bottom of the glass jar.
- → Wrap a towel around the jar to slow the cooling process; slower thermal decay produces significantly larger, gem-quality crystal facets.
Safety First
Wear safety goggles; handle boiling water with heat-resistant gloves. Borax is not edible.
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Step-by-Step Instructions
Step 1
Bend purple and blue pipe cleaners into a hollow concave hollow sphere or hollow ring to serve as the geode rock base.
Step 2
Boil 3 cups of water and stir in 9 tablespoons of borax powder one at a time until no more dissolves and the solution is clear and supersaturated.
Step 3
Add 5 drops of food dye, pour the liquid into a wide-mouth glass jar, and suspend the pipe cleaner into the liquid using string tied to a pencil resting on the rim.
Step 4
Wrap the jar in a towel and leave undisturbed for 12–18 hours, then extract and inspect the dense, light-refracting crystal formations under a bright lamp.