The 5-element (Co-Ni-As-Ag-Bi) veins of the Kongsberg mines in Norway created probably the biggest silver mine in Europe.
According to numerous investigators, the veins are dated at 265 m.y. and the process of hydrothermal alteration brought the metals from the black shales of the Oslo region through metamorphic rocks of orogenies from 1.6 b.y. and 1.1 b.y.
The ancient Minoans originally worked the area about 1,500 years BC and left a description of the ore on site on a slab of outcropping granite: "soft and pure" (of the silver) in hieroglyphic Linear A "writing".