Roger Weller, geology instructor
tarnished native copper
Keweenaw Peninsula, Michigan
This specimen of native copper comes from the Keweenaw peninsula of northern
Michigan. The green mineral is epidote and the white mineral is calcite. The copper
can be recognized by its reddish tarnish and by its shape. Copper is a metal and
malleable; no brittle mineral could form such large masses attached by such small
connecting points without breaking off. Michigan copper also displays a property
called "hackly". When you pick up a piece of copper, barehanded, it also grabs
you because of sharp projections. After a day of collecting copper specimens,
you will find your fingers all scratched.
Photo is copyright free for non-commercial educational uses.
Just credit photo to R.Weller/Cochise College.