The dumps of the closed copper mine Wolverine # 2 near to Kaersage represent a very interesting place of discovery for extraordinary agate formations. Beside the minerals prehnite, calcite, datolite and copper the cavities in a amygdaloite are bearing again and again also white to creamy colored agate. It comes rarely in these almonds to the formation of beautiful pseudomorphs “from copper to agate”.
Copper as microscopic inclusion mineral in Lake Superior agates is not unusual. One makes it responsible however even for the greenish colours, which can be shown by the Lake Superior agates, (it is present here then submicroscopically small.) Macroscopically recognizably copper in agates represents an uncommon rarity.
Copper is rather irregularly distributed in the agate nodules of the Wolverine #2 mine. Now and then it concentrates in certain situations in the agate-banding as little dots. Only rarely complete rings are formed. Often the copper arises only in the boundary region. A Companion can be also the mineral cuprite in this situation. There are again and again also a growing of copper in nodule fillings of Prehnit or Datolith, in addition, nodules in a high percentage from solid copper exist.
Further information is given by Professor Dr. Werner Lieber in the Mineralienwelt 5, 2007 in the article “phenomena in the kingdom of agates: Native copper in the agate”