My father’s collection of native copper contains 22 pieces (now a Cassy Chan’s collection :D), all of which were excavated from the copper mines of Michigan during the 1990's. Among the 22 specimens, these are my favorite ones:
Copper is a native metal which has been utilized by humans since ancient civilizations for ornaments and coinage. The name copper is derived from the Latin word “cuprum”, which refers to the island (now Cyprus) where the Romans obtained their copper supply. Copper is a low reactive metal, unlike gold, it will react but slowly. Because of its low reactivity, combined with its malleability makes it ideal for use in architecture. Examples of which are as follows:
The Royal Observatory located on Blackford Hill in Edinburgh, United Kingdom
The Statue of Liberty in New York, United States
These famous statue and architecture have hardly corroded at all due to copper cladding – a naturally formed pale green coating of copper salts called patina. Native copper has a distinctive rosy copper red color and it possesses a red streak. I have seen on the mineral market some solvent cleaned and shined copper which present an artificial red color in its fleshy hue. The chemical treated native copper lacks the shiny, highly reflective luster typical of metals. If you exposed your native copper specimens to air for long they may tarnish to black oxide or green carbonate like the patina. Keeping them in a good plastic display case and away from moisture is ideal, never place your beautiful native copper piece in the bathroom! Well, am sure a little rubber duck will live :P
Native copper is of the isometric crystal system and fine specimens with well-formed crystal faces are rare. I personally prefer the arborescent, dendritic branching crystal structure as they are more artistic and aesthetic, especially those mixed with minerals like epidote, malachite and azurite adding great coloration and pizzazz. Like the specimens shown below, they are the rest of the gorgeous 22 pieces that I have:
A piece of native copper from the Michigan was sold in the Christie’s London Auction in May 2019 at the price of GBP 12,500 (https://www.christies.com/lotfinder/Lot/a-specimen-of-native-copper-michigan-usa-6204095-details.aspx). Well crystallized specimens are highly valued and are very much sought after. My friends, do keep an eye out for the surprises to come :D
