Science & Discovery Projects6-12 years
Easy
10 Minutes
Grow Vibrant Epsom Colorful Salt Crystals
Bilal Şentürk
Maker
What You'll Need
- Epsom salt (MgSO₄·7H₂O)
- Hot water (just below boiling)
- Measuring cup
- Stirring rod or spoon
- Clear jar or container
- Food colouring (optional)
- “Seed” material: string, small stone, shell, or decorative trinket (optional)
- Tray or protective mat
- Lid or plastic wrap
Safety First!
- !Handle hot water with care to avoid burns.
- !Work on a stable, heat-resistant surface.
- !Supervise children when using hot liquids.
- !Wipe up any spills immediately to prevent slipping.
- !Store solutions and chemicals out of reach of pets and small children.
Let's Make It! Step-by-Step Guide
1
Prepare the Saturated Solution
Step 1 of 5
Heat your measured water until very warm, then gradually stir in Epsom salt until no more dissolves and tiny crystals start to appear at the bottom.
The Science Behind It
As water heats up, its ability to dissolve salt increases. When you create a “supersaturated” solution—one that holds more dissolved salt than it can under normal conditions—cooling and evaporation force the excess salt out of solution. Those salt molecules re-arrange themselves into orderly, repeating patterns: crystals. Over time, water escapes by evaporation, and more salt deposits onto your seed, building up larger, well-formed crystals.
Helpful Tips
- Pour solution down the side of the jar to avoid disturbing any early crystals.
- Rotate your seed gently each day to encourage even growth.
- Use a clear container for the best viewing of internal crystal structure.
- If crystals grow too slowly, move the jar to a slightly warmer spot.
Try These Variations!
- 1Different Salts: Experiment with table salt, borax or alum for varied crystal shapes.
- 2Layered Crystals: Prepare separate coloured solutions, let one layer set, then carefully add a second colour on top.
- 3Crystal Geodes: Fill eggshell halves with seed crystals, then pour your solution in to form geode-like formations.
- 4Mica Sparkle: Sprinkle mica powder into the solution for glittery, iridescent crystals.