This practical involves forming coloured silicate crystals in a beaker.
Sodium silicate solution is poured into a beaker to a level of around 3-4cm and then hot water is stirred in to a depth of around 10-15cm. Stir until well mixed and leave to still.
Using forceps, place small crystal of the metal nitrates or sulfates into the liquid making sure they do not touch each other.
Cover the jar using a gas jar lid and leave for 15-24 hours.
Equipment required (per set):
- Beaker or transparent glass jar
- Gas jar lid or cover
- Stirring rod
- Sodium silicate solution (irritant)
- Hot deionised (distilled) water
- Cobalt nitrate (irritant)
- Magnesium nitrate
- Manganese sulphate
- Nickel nitrate (harmful)
- Iron (III) nitrate (irritant)
Only a few crystals of each metal should be used. The beaker should not be moved once the crystals have started growing as they may fall apart.
The different metals will produce different coloured crystals.