A crystal is an organisation of atoms, or molecules. Crystals grow by a nucleation, a process in which atoms or molecules crystallise. Solute particles contact and connect in a process that continues outwardly. Every crystal is different. Sugar crystals are oblong and slanted at the ends. Salt crystals are cubic. Some elements, such as carbon, can make more than one crystalline form. There are simple and more complex ways to grow crystals. The instructions that follow are how to make your own crystals, a simple salt crystal garden.
Grow a salt crystal garden. Make a saturated solution. Combine salt, bluing, water and ammonia into a measuring cup. Use caution with clothing, skin and eyes as your pour the ingredients. Coat a shallow glass bowl with petroleum jelly to assure crystallisation on the porous material and not on the bowl.
Place clay shards or briquettes in a shallow glass bowl. If using charcoal, soak briquettes in water for 15 minutes before pouring the solution. Also, charcoal needs to have the solution level remain at least halfway up the briquettes. Sprinkle 2 tbsp salt over the porous material the first and second days to promote crystallisation.
Pour bluing solution over prepared porous materials. Crystals will form in about 6 hours and will continue to form for 3 days. Humidity, temperature and air currents affect how long the crystal garden will flourish. Steady and warm temperature, low humidity and no drafts are best conditions.
Maintain your crystal garden. Add more bluing solution on the third day to promote more growth. Do not allow solution to come in contact with formed crystals. Eventually, crystals will grow on the bowl.
Crystals easily wash off of glass bowls. Crystals are fragile and are hard to keep in a dried state.
Do not allow children to do this experiment alone. Do not allow children to handle even the most common household chemicals, such as laundry chemicals.