A warm reddish gold in colour, copper is the most easily recognized of all
metals. It is quite soft, and sometimes found pure in
nativeform - which is why it was one of the
first metals people learned to use. The oldest
knives found, dating back 6,000 years, are
made of copper. Pure copper is often found
in sulphide-rich veins in warm desert
areas, or in cavities in-ancient lava flows.
Like silver, it often grows in branching masses and
tarnishes quickly. Yet the tarnish is bright green, not
black, and a copper deposit is
often revealed by bright green stains
on rocks called copper bloom. As a
nativeelement, copper is quite rare,
so most of the copper used today
comes from ores such
aschalcopyrite.