A large, low-grade deposit formed around a cooling intrusion, most often carrying copper with gold or molybdenum.
A large, low-grade disseminated ore deposit typically containing copper, molybdenum, and sometimes gold. Porphyry deposits form from hydrothermal fluids associated with intrusive igneous rocks and are among the world's largest metal sources.
Porphyries supply most of the world's copper and a good deal of its molybdenum. They are enormous, mineable from surface, and almost always beyond what a junior can build alone.