The last session of the day was our attempt at creating a chemical garden, which is an experiment involving solid metal salts in an aqueous solution of sodium silicate (waterglass). This results in the generation of crystals which, as the name promptly suggests, grow in a plant-like structure. Very interesting results in the pictures. See below for an example of how to conduct this experiment.
From the next day:
A couple of projects elaborating on this. Roots installation by Roman Kirschner, and Phantom Lucid Messenger by Herwig Weiser.
Practical guide:
Here as a salt, copper (II) sulfate is used, which is toxic, it should not be ingested, and gloves are a recommended safety precaution.
Remember to keep your working tools and surfaces as clean as possible for the purest possible crystals.
Materials
- Copper (II) sulphate in powder form (CUSO4)
- Deionised/distilled water
- Shallow dish
- Glass beaker
- Button or similar object
- Sandpaper
- Nylon thread or plastic-coated wire
- Stirring rod
- Coffee filter
- Gloves
- Safety glasses
Instructions
To make your saturated solution:
- The hotter your water the more copper (II) sulphate you can add
- Fill the beaker with deionised water and heat
- Remove the beaker from the heat and stir in the copper (II) sulphate powder, until no more will dissolve, and there are no traces left at the bottom
- The colour of your liquid should now be deep blue and opaque
For larger crystals with better shape, you will need a seed crystal to start with:
- Roughen the surface of the button with sandpaper, to help allow the crystals to attach
- Pass the thread through the button, with extra thread to later hang it in the beaker
- Fill the shallow dish with some of your saturated solution
- Place the button in the dish, so that it is covered by the solution, and crystals may form
- Let this sit for a few hours or even overnight, undisturbed, allowing for evaporation (happening faster in a warm place)
- After the solution has evaporated, crystals will be left on the button—your “seed” crystal is ready
Growing (and harvesting) your crystal garden:
- Take a clean beaker and fill it with your saturated solution
- Hang your seed crystal halfway down in the solution, so that it doesn’t touch the sides
- Placing a coffee filter on top of the beaker will protect from contamination due to dust
- Let it grow without disturbance
- Should you notice crystals growing on the side of the beaker, take the seed crystal out and place it into another beaker of solution–as other crystals will slow its growth due to competition
- A longer growing time and higher saturation of solution will yield a correspondingly bigger crystal
- When your crystal has grown to a size ready for “harvesting”, remove it from the beaker and let it dry out on a paper towel
- Keeping your crystal in a sealed container will prevent drying out and colour fading