HEMIMORPHITE, SANTA EULALIA, CHIHUAHUA. MEXICO (cabinet)

Hemimorphite, represented by the chemical formula Zn4(Si2O7)(OH)2·H2O, is a constituent of the mineral calamine. This silicate mineral, along with smithsonite (ZnCO3), has been traditionally extracted from the upper regions of zinc and lead ores. Initially, both minerals were thought to be identical and categorized under the name calamine. However, in the latter part of the 18th century, it was revealed that these distinct compounds coexist within calamine, despite their close resemblance.