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Monetite is a phosphate mineral formed by the reaction of the chemicals in bat guano with calcite substrates and is commonly found in caves. The analog of the mineral monetite CaHPO4 has been synthesized and the Raman and infrared spectra of the natural monetite originating from the Murra-el-elevyn Cave, Eucla, Western Australia, compared. Monetite is characterized by a complex set of phosphate bands that arise because of two sets of pairs of phosphate units in the unit cell. Raman and infrared bands are assigned to , OH stretching and bending vibrations. Infrared bands at 1346 and 1402 cm−1 are assigned to POH deformation modes. Vibrational spectroscopy confirms the presence of monetite in the cave system.

In order to mimic the formation of archerite in cave minerals, the mineral analogue has been synthesised. The cave mineral is formed by the reaction of the chemicals in bat guano with calcite substrates. X-ray diffraction proves that the synthesised archerite analogue was pure and more pure than the natural cave mineral. The vibrational spectra of the synthesised mineral are compared with that of the natural cave mineral from the Murra-el-elevyn Cave, Eucla, Western Australia. Raman and infrared bands are assigned to H 2 PO 4 - , OH and NH stretching and bending vibrations. The Raman band at 917 cm−1 is assigned to the HOP stretching vibration of H 2 PO 4 - units. Bands in the 1200–1800 cm−1 region are associated with NH 4 + bending modes. Vibrational spectroscopy enables the molecular structure of archerite analogue to be analysed.

Some minerals are formed which show poorly defined X-ray diffraction patterns. Vibrational spectroscopy offers one of the few methods for the assessment of the structure of the oxyanions in such minerals. Among this group of minerals is mallestigite with formula Pb 3 Sb 5+ (SO 4 )(AsO 4 )(OH) 6 ·3H 2 O. The objective of this research is to determine the molecular structure of the mineral mallestigite using vibrational spectroscopy. Raman and infrared bands are attributed to the AsO 4 3− , SO 4 2− and water stretching vibrations. Mallestigite is a mineral formed in ancient waste dumps such as occurs at Mallestiger, Carinthia, Austria and as such is a mineral of archaeological significance.

Some minerals are colloidal and show no X-ray diffraction patterns. Vibrational spectroscopy offers one of the few methods for the assessment of the structure of these types of mineral. Among this group of minerals is pitticite simply described as Fe, AsO4, SO4, H2O. The objective of this research is to determine the molecular structure of the mineral pitticite using vibrational spectroscopy. Raman microscopy offers a useful method for the analysis of such colloidal minerals. Raman and infrared bands are attributed to the AsO 4 3 - , SO 4 2 - and water stretching vibrations. The Raman spectrum is dominated by a very intense sharp band at 983 cm−1 assigned to the SO 4 2 - symmetric stretching mode. A strong Raman band at 1041 cm−1 is observed and is assigned to the SO 4 2 - antisymmetric stretching mode. Low intensity Raman bands at 757 and 808 cm−1 may be assigned to the AsO 4 3 - antisymmetric and symmetric stretching modes. Raman bands observed at 432 and 465 cm−1 are attributable to the doubly degenerate ν2 ( SO 4 ) 2 - bending mode.

Some minerals are colloidal and show no X-ray diffraction patterns. Vibrational spectroscopy offers one of the few methods for the determination of the structure of these minerals. Among this group of minerals is pitticite, simply described as (Fe, AsO(4), SO(4), H(2)O). In this work, the analogue of the mineral pitticite has been synthesised. The objective of this research is to determine the molecular structure of the mineral pitticite using vibrational spectroscopy. Raman and infrared bands are attributed to the AsO(4)(3-), SO(4)(2-) and water stretching and bending vibrations. The Raman spectrum of the pitticite analogue shows intense peaks at 845 and 837cm(-1) assigned to the AsO(4)(3-) stretching vibrations. Raman bands at 1096 and 1182cm(-1) are attributed to the SO(4)(2-) antisymmetric stretching bands. Raman spectroscopy offers a useful method for the analysis of such colloidal minerals.

In order to mimic the chemical reactions in cave systems, the analogue of the mineral stercorite H(NH 4 )Na(PO 4 )·4H 2 O has been synthesised. X-ray diffraction of the stercorite analogue matches the stercorite reference pattern. A comparison is made with the vibrational spectra of synthetic stercorite analogue and the natural Cave mineral. The mineral in nature is formed by the reaction of bat guano chemicals on calcite substrates. A single Raman band at 920 cm −1 (Cave) and 922 cm −1 (synthesised) defines the presence of hydrogen phosphate in the mineral. In the synthetic stercorite analogue, additional bands are observed and are attributed to the dihydrogen and phosphate anions. The vibrational spectra of synthetic stercorite only partly match that of the natural stercorite. It is suggested that natural stercorite is more pure than that of synthesised stercorite. Antisymmetric stretching bands are observed in the infrared spectrum at 1052, 1097, 1135 and 1173 cm −1 . Raman spectroscopy shows the stercorite mineral is based upon the hydrogen phosphate anion and not the phosphate anion. Raman and infrared bands are found and assigned to PO 4 3− , H 2 O, OH and NH stretching vibrations. Raman spectroscopy shows the synthetic analogue is similar to the natural mineral. A mechanism for the formation of stercorite is provided.