In 1913, Maisel explained, an Oregon state psychiatric institution began to cremate the remains of its unclaimed patients. Their ashes were then stored inside individual copper canisters and moved into a small room, where they were stacked onto pine shelves... Over time, however, the canisters have begun to react chemically with the human ashes held inside them; this has thus created mold-like mineral outgrowths on the exterior surfaces of these otherwise gleaming cylinders.

-bldg blog