Chemical gardens from silicates and cations of group 2: a comparative study of composition, morphology and microstructure

We have compared the behaviour of the chloride salts of the cations Ca(2+), Sr(2+) and Ba(2+) of Group 2 of the Periodic Table in the formation of chemical gardens in silicate solutions. We performed analyses of morphology, composition and microstructure using environmental scanning electron microscopy (ESEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDX). We have identified different growth regimes in these salts (jetting and budding), which are dependent on the concentration of the silicate solution. The behaviour is similar for all the cations but reactivity decreases down the group and is directly proportional to the solubility of the salts: Ca(2+) > Sr(2+) > Ba(2+).