what is this stuff? any geo's about?, page-24

Whats bad about it? Its still copper and therefore still valuable isn't it?

Fools Gold only because of its color....

http://mineral.galleries.com/minerals/sulfides/chalcopy/chalcopy.htm

Chalcopyrite (or copper pyrite), looks like, and is easily confused with Pyrite, FeS2. Chalcopyrite is one of the minerals refered to as "Fool's Gold" because of its bright golden color. But real gold is a more buttery yellow and is ductile and malleable.