Date: April 2006
Why are cast iron cook-ware black in color? Iron is
silver colored. Iron oxide is reddish. What is the composition of
the black iron?
Cast iron contains carbon, which makes it appear slightly different
from pure iron, but the main reason the cookware is black is that cast
iron cookware takes on a patina from the cooking, both from the food
and the heat. This deepens the color to black. New cast iron cookware
has the gray color.
David Brandt, P.E.
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Update: June 2012