If we could know the exact circumstances which affect it, we could foretell what now seems to us only caprice of thought, as well as what now seems to us only caprice of crystal: nay, so far as our knowledge reaches, it is on the whole easier to find some reason why the peasant girls of Berne should wear their caps in the shape of butterflies; and the peasant girls of Munich theirs in the shape of shells, than to say why the rock-crystals of Dauphine should all have their summits of the shape of lip-pieces of flageolets, while those of St. Gothard are symmetrical, or why the fluor of Chamouni is rose-colored, and in octahedrons, while the fluor of Weardale is green, and in cubes.
"The Ethics of the Dust"
John Ruskin