Chemical garden Chemical garden A chemical garden is an experiment in chemistry usually performed by adding metal salts such as copper sulfate or cobalt(II) chloride to an aqueous solution of sodium silicate (otherwise known as waterglass). This results in growth of plant-like forms in minutes to hours. The chemical garden was first observed and described by Johann Rudolf Glauber in 1646. In its original form, the chemical garden involved the introduction of ferrous chloride (FeCl) crystals into a solution of potassium silicate (KSiO). The chemical garden relies on most transition metal silicates being insoluble in water and coloured. A metal salt such
Cobalt zinc oxide), and cobalt violet (cobalt phosphate) are used as artist's pigments because of their superior chromatic stability. Aureolin (cobalt yellow) is now largely replaced by more lightfast yellow pigments. Cobalt-60 (Co-60 or Co) is useful as a gamma-ray source because they can be produced in predictable quantity and high activity by bombarding cobalt with neutrons. It produces gamma rays with energies of 1.17 and 1.33 MeV. Cobalt is used in external beam radiotherapy, sterilization of medical supplies and medical waste, radiation treatment of foods for sterilization (cold pasteurization), industrial radiography (e.g. weld integrity radiographs), density measurements (e.g. concrete density