Hemimorphite, Zn4(SiO7)(OH2).H2O. Henfwlch mine, west Wales. The beauty of the hemimorphite crystals in these specimens can only he appreciated under a microscope. The Henfwlch mine is noted for the presence of hemimorphite, which is a zinc ore found in the weathering zones of sphalerite deposits. See hemimorphite 2 for more specimens.