"But often I found myself going up over the hill into the small and quaint town of Julian." Julian recently had a rather important geological/gemological disco

"But often I found myself going up over the hill into the small and quaint town of Julian." Julian recently had a rather important geological/gemological discovery happen - crystals of emerald, bisected by citrine - yet it's all one and the same crystal, and it wasn't caused by the emerald breaking and citrine filling the fracture. The citrine acts as a sort of 'barrier' where you can see inverse concentrations of various elements on either side of the citrine.