Growing new flowers in the chemical garden – cobalt chloride

What is it?

Some of you may have been lucky enough to have grown your own chemical garden at some stage. This works by taking powders of metal salts (that are usually brightly coloured) and adding them to a water solution of sodium silicate (waterglass). The result when you add these to a water bath is that the mixtures seem to 'grow' into plant-like features. The team at Periodic Videos explained it really well here:

Just this week some researchers have discovered that when you confine the chemical garden solutions to just two dimensions, you can get some lovely new shapes growing – including some crystal 'flowers'. They used cobalt chloride, altered the strength of the solutions, and took videos of what grew. They've made a super sum-up video about their work, which you can see here.

Where did the crystal structure come from?

The structure of cobalt chloride was first determined by Grime and Santos in 1934, and you can read their lovely paper on it here.

Tags: colours   simple   demonstration