Native Copper

This wiry aggregate, shown about twice life size, formed as metal-bearing fluids worked their way into channels and pore spaces in a preexisting matrix, probably near a volcanic zone. There are many different scenarios that mobilize and redeposit copper in the upper crust. Because native copper corrodes fairly quickly at surface conditions, specimens like this don't last long (unlike gold).

Copper nuggets are well known in places like Minnesota or Michigan's Upper Peninsula, which was a copper district for many years. There copper metal appears in extremely old rocks of the Canadian Shield. Native copper has a distinctive copper-colored streak.

Copper was not as useful for the ancients as the alloy bronze, which includes tin metal and is much more durable. Today copper is one of the most important metals, used in electrical equipment, alloys, coatings, and computer chips.

Native copper is no longer an important source of the metal. Today copper comes from huge low-grade deposits, mined by large companies that have a very small profit margin but make up for it in volume. Impurities in copper, including silver and gold, are important byproducts.

Other Hydrothermal Vein Minerals