The copper ores of the Lake Superior district, and of a few small deposits in the eastern United States, contain small percentages of native copper in pre-Cambrian volcanic flows or in sediments between the flows.
Native copper, mined in the Lake Superior region, is the source of 8 to 10 per cent of the world's copper supply.
On Keweenaw Point, Michigan, deposits of native copper formed in this manner in the "Nonesuch" beds have been worked on a commercial scale.
The Lake Superior mines are unique in being deposits of native copper.
Native copper occurs in the Lake Superior region, but the demands of commerce are supplied from chalcopyrite or copper pyrites, and tetrahedrite or gray copper ore.
The common ore is native copper, often associated with native silver, the two remaining, chemically, quite distinct.
Nearly every part of this broad and extensive dyke which has been examined, yields veins, and masses of native copper, or copper ores.
The rock consists of a mass of native copper in a tabular boulder of serpentine.
In a boulder of serpentine rock, I found an imbedded mass of native copper, of two pounds' weight.
A block of native copper now in the National Museum at Washington is described by the Père Charlevoix as a sacred object of veneration by the Indians of Lake Superior, on which a young maiden had been offered in sacrifice.
It has been generally estimated here, since its arrival, to weigh between six and seven thousand pounds, or about three and a half tons, and is by far the largest known and described specimen of native copper on the globe.
It is upwards of twenty-three years since I first visited this remarkable specimen of native copper, in the forests of Lake Superior.
The above list will hopefully provide you with a few useful examples demonstrating the appropriate usage of "native copper" in a variety of sentences. We hope that you will now be able to make sentences using this group of words.
