Chalcopyrite, Pyrite, Magnetite and Byssolite     French Creek Mines, St. Peter, Chester Co., PA. Ex. Dr. Steve Chamberlain collection, circ. 1936. This is one of those old classic from a noteworthy east coast occurrence. This hefty piece of sphalerite matrix measures approx 8 cm wide and contains well-formed magnetite crystals (small) and a network of large hoppered chalcopyrites. Their luster varies from very bright to dull and some areas have a good deal of iridescence. There are high luster pyrites in a few places. There is also some calcite which was not etched away when this piece was prepared for sale 70 plus years ago. It is thick and stable with well protected damage-free crystals. It does not display especially well from the sides. A substantial piece from a classic locale. $295