Vibrational spectroscopy of the sorosilicate mineral hemimorphite Zn4(OH)2Si2O7 · H2O

Raman spectroscopy complimented by infrared spectroscopy has been used to study the mineral hemimorphite from different origins. The Raman spectra show consistently similar spectra with only one sample showing additional bands due to the presence of smithsonite. Raman bands observed at 3510–3565 and 3436–3455 cm−1 are assigned to OH stretching vibrations. Using a Libowitzky type formula, these OH bands provide hydrogen bond distances of 0.2910, 0.2825, 0.2762 and 0.2716 pm. Water bending modes are observed in the Raman spectrum at 1633 cm−1. An intense Raman band at 930 cm−1 is attributed to SiO symmetric stretching vibration of the Si2O7 units. Raman bands observed at 451 and 400 cm−1are attributed to out-of-plane bending vibrations of the Si2O7 units. Raman bands at 330, 280, 168 and 132 cm−1 are assigned to ZnO and OZnO vibrations.

Raman spectroscopy complimented by infrared spectroscopy of the mineral hemimorphite from different origins shows OH bands providing hydrogen bond distances of 2.910, 2.825, 2.762 and 2.716 Å.Figure optionsDownload as PowerPoint slide