In-Situ X-ray Photoelectron Spectroscopy and Raman Microscopy of Roselite Crystals, Ca2(Co2+,Mg)(AsO4)2 2H2O, from the Aghbar Mine, Morocco

Roselite from the Aghbar Mine, Morocco, [Ca2(Co2+,Mg)(AsO4)2 2H2O], was investigated by X-ray Photoelectron and Raman spectroscopy. Spectroscopy revealed a cobalt to magnesium ratio of 3:1. Magnesium, calcium showed single bands associated with unique crystallographic positions. The oxygen 1s spectrum displayed two arsenate group crystal water. Arsenic 3d exhibited close that ratio, indicative local arsenic environment being sensitive substitution for cobalt. symmetric antisymmetric modes were all split observed around 865 818 cm−1, while found 980 709 cm−1. An overlapping water-libration mode at region 400–500 cm−1 splitting 499, 475, 450 425 300–400 corresponding bending 377, 353, 336 304 below 300 assigned lattice modes.