Roger Weller, geology instructor
firstname.lastname@example.org copyright 2010-R.Weller
copper within a calcite crystal-2
from Keweenaw Peninsula, Michigan
Copper within the calcite is untarnished.
Photo is copyright free for non-commercial educational uses.
Just credit photo to R.Weller/Cochise College.
Specimen on display at Cranbrook Institute of Science, Bloomfield Hills, Michigan.