NATIVE COPPER SPECIMEN [from Caledonia mine] 23CTS [MX1714 ]

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NATIVE COPPER SPECIMEN

This is a natural specimen mined at the Caledonia mine in Ontonagon Co USA.It has been cleaned and should retain its copper red colour.Ideal as a specimen or made in to a natural pendant.

Weight 23 cts app

Size 32 x 27x4 mm app

Copper, as native copper, is one of the few metals to naturally occur as an un-compounded mineral. Copper was known to some of the oldest civilizations on record, and has a history of use that is at least 10,000 years old. Some estimates of copper's discovery place this event around 9000 BC in the Middle East .A copper pendant was found in what is now northern Iraq that dates to 8700 BC. Color

Copper has a reddish, orangish, or brownish color because a thin layer of tarnish(including oxides) gradually forms on its surface when gases (especially oxygen) in the air react with it. But pure copper, when fresh, is actually a pinkish or peachy metal. Copper, caesium and gold are the only three elemental metals with a natural color other than gray or silver. The usual gray color of metals depends on their "electron sea" that is capable of absorbing and re-emitting photons over a wide range of frequencies. Copper is a metal that does not react with water , but the oxygen of the air will react slowly at room temperature to form a layer of brown-black copper oxide on copper metal.

Spedizione

Fornitore di spedizioni	Spedizione a Australia	Spedizione nel resto del mondo	Spedizione combinata ( Australia )	Spedizione combinata (resto del mondo)
FedEx	/ 3 giorni	/ 10 giorni	su ordini con 2 di articoli o più	su ordini con 2 di articoli o più
Registered Shipping	/ 7 giorni	/ 21 giorni	su ordini con 2 di articoli o più	su ordini con 2 di articoli o più