Cofer district, Virginia, USA

Major Minerals:

Pyrite, sphalerite, chalcopyrite

Minor Minerals:

Galena, gahnite

Trace Minerals:

Include monoclinic pyrrhotite, tetrahedrite-tennantite, arsenopyrite, bournonite, electrum, graphite


Pyrite and sphalerite form alternating layers that reflect their original volcanogenic formation. Pyrite has recrystallized and shows growth zonation. Sphalerite stars occur as inclusions within chalcopyrite. Chalcopyrite as chalcopyrite disease is common within sphalerite


Craig, 1983