Lake Superior Copper District, Michigan

1930s

This is a rather unusual and unique specimen. The specimen is composed of massive, cleaved white Calcite which is attached on one side to basalt matrix. At one end, there is a curved layer of Copper most of which is on the surface of this massive Calcite (although there is some embedded in it also). Around the edges of the Copper, there is a secondary growth of clear Calcite crystals overlaying the Copper, but in the center, the Copper is exposed. This gives the overall appearance of a vug of Copper. The exposed Copper is for the most part a flat crystallized surface, but there are some small wires rising from it (see the last picture). The unusual thing is how bright the copper is. This is common with Copper included in Calcite, but not exposed Copper. Furthermore, the specimen had been stored for about 40 years in a damp basement in southeastern Michigan. It is amazing the Copper is so bright. The specimen was in the collection of Claude Bullen. Claude was originally from Cornwall. When he was a young man, he immigrated to the United States shortly after the turn of the century (1900). He moved to the Keweenaw Peninsula where he was an engineer for the Copper mines. This specimen was purchased in the 1930s. Claude later moved to Ypsilanti, Michigan where he passed away in the 1960s. His collection remained in his home's basement until a few years ago when it was put up for sale with the help of the Huron Hills mineral club from nearby Ann Arbor. It was at this sale, that I purchased the specimen. The specimen is in excellent condition with no appreciable damage to the Calcite crystals around the "vug". Because the bottom is basically cleaved Calcite, it stands up well.

5.3 x 4.4 x 4.7 cm

Sold Specimen retained as part of the Minerals Sold But Not Forgotten Galleries