Effect of Temperature on Calcium-Based Chemical Garden Growth

Hydrothermal vents maintain far-from equilibrium conditions that may have provided the necessary settings for the origin of life. To understand reactions under these physicochemical conditions, scientists have turned to the classic demonstration experiment, chemical gardens. The self-organization of precipitate tubes separates high and low pH environments similarly to the naturally occurring geological structures. Here, we report calcium-based chemical gardens forming in solutions containing anions of silicate, carbonate, or a mixture of the two in 100 °C and 23 °C environments. Under high temperature conditions, chemical gardens tend to have faster average growth velocities and form taller structures. We measure the composition of the precipitate tubes using Fourier transform infrared spectroscopy and find the formation of all polymorphs of calcium carbonate along with calcium silicates.