Front:
EARLY CO*PER MINE
ASHING
SEP
ON
17
1992
20065
Minerals USA
29
Copper
KOSLOW
DC
Back:
COPPER
First Day of Issue: September 17, 1992
First Issue Location: Washington, D.C.
Although copper is found adhered to other minerals such
as malachite, bornite and cuprite, it is the only metal that
commonly occurs in a free metallic state — a native form.
Copper in this pure form was first used by Neolithic man
as a substitute for stone. Copper's malleability allows it to
easily be shaped into wire and, with the exception of
silver, it conducts electricity and heat better than any
other metal. Hence, the majority of copper produced in
the world is used for electrical purposes. The greatest
deposit of copper ore in the United States is found in
northern Michigan. Here, along Lake Superior's
Keeweenaw Peninsula, a four-mile-wide belt of native
copper extends for 100 miles. This abundant metal is also
found in the body chemistry of mollusks, arthropods and
humans. In blue-blooded mollusks and crustaceans, it
plays the vital role of transporting oxygen in the hemo-
cyanin. Copper appears as a trace element in humans and
acts as a catalyst in the formation of hemoglobin.
No. 92-118
First Day of Issue Postcard Collection
©1992 Fleetwood® Cheyenne, WY 82008-0001
Original painting for the First Day of Issue Postcard by Howard Koslow
Heetwood
