Pyrite-Quite recently there have been obtained from limestone cavities in Lee County some small but very perfect pyrite crystals. The faces are brightly reflecting and meet in sharply defined edges. The more common crystallographic forms are the pentagonal dodecahedron, or pyritohedron, and the cube, with all gradations between the two. Though small they are perhaps the most perfect crystals of this mineral found in the state up to the present time.
Proceedings of the Iowa Academy of Sciences
©1892 Iowa Academy of Science, Inc.
Keyes, Charles Rollin
"Iowa Mineralogical Notes,"
Proceedings of the Iowa Academy of Science, 1(Pt. 3), 18-22.
Available at: https://scholarworks.uni.edu/pias/vol1/iss3/7