Gold, precious, sacred, and inert, is a deeply unreactive element. Because it is far too resistant to acid baths, the gold surface must be abraded to enable an ingress path for the acid solution to the brass substrate beneath, which is intensely reactive. This necessary abrasion pattern is etched with a rock fragment. This is the seed, whereby minute variations in hand pressure, technique, and rock texture are the ground from which a unique and one-of-a-kind pattern blooms.