This image shows a hemihedral crystal of pyroxene, whose forms are (c), (b), (a), (m), (o), and (u).
George Huntington Williams, Ph.D. Elements of Crystallography for Students of Chemistry, Physics, and Mineralogy (New York, NY: Henry Holt and Company, 1892)
3072×2771, 500.2 KiB
1024×923, 40.4 KiB
640×577, 22.8 KiB
320×288, 9.9 KiB