Dims: 9.70x5.64x1.40in (24.65x14.31x3.55cm)
Wt: 43.03oz (1220g)
Keweenaw, Michigan, USA
While not a natural mineral specimen, this is still an interesting piece of mineral art. It was made by pouring molten natural copper (melted, not refined, native copper mined in Keweenaw) into a pile of wet straw, then pouring acid to give exposed copper a green tarnish, then finally polishing some surfaces to expose the copper within.