Copper is a native element and often occurs in fine-grained volcanic rocks such as basalt. It is red and orange in color until exposed to oxygen which can cause it to turn green and black over time. It was one of the first metals to be used by humans and was the first to be smelted from ores. Calcite is made of calcium carbonate and is found in sedimentary, metamorphic, and igneous rocks. This specimen features copper enclosed in colorless calcite and was found near Lake Superior in Michigan. It was sold by George L. English & Co.
Copper Formula: Cu Calcite Formula: CaCO3
circa 1888 – 1898
George L. English & Company George L. English and Company was a mineral business founded by George L. English in Philadelphia, Pennsylvania in 1887 with partner Edwin C. Atkinson. In 1890 his business expanded to New York City and in 1905 the entire business and stock was bought by Ward's Natural Science Establishment.