06-13. Calcite #3.
There is a cave somewhere in France – The crystal cave of Bellacroix it is called. It was discovered somewhere in the 1700s or 1800s. Beautiful calcite adorned its ceiling. It got vandalized so many times – locals had to block the entrance with a metal grid. I hope, the gate maker got inspired by the beautiful geometry of its crystal. To get this pattern, I just took the outline of the binding between the atoms and multiplied it several times.
From a resource by Markgraf and Reeder.