title: A Raman spectroscopic comparison of calcite and dolomite.
abstract: Raman spectroscopy was used to characterize and differentiate the two minerals calcite and dolomite and the bands related to the mineral structure. The (CO3)(2-) group is characterized by four prominent Raman vibrational modes: (a) the symmetric stretching, (b) the asymmetric deformation, (c) asymmetric stretching and (d) symmetric deformation. These vibrational modes of the calcite and dolomite were observed at 1440, 1088, 715 and 278 cm(-1). The significant differences between the minerals calcite and dolomite are observed by Raman spectroscopy. Calcite shows the typical bands observed at 1361, 1047, 715 and 157 cm(-1), and the special bands at 1393, 1098, 1069, 1019, 299, 258 and 176 cm(-1) for dolomite are observed. The difference is explained on the basis of the structure variation of the two minerals. Calcite has a trigonal structure with two molecules per unit cell, and dolomite has a hexagonal structure. This is more likely to cause the splitting and distorting of the carbonate groups. Another cause for the difference is the cation substituting for Mg in the dolomite mineral.
authors.affiliation: Datang International High Alumina Coal R&D Center, Hohhot 010050, PR China.
authors.forename: Junmin
authors.initials: J
authors.lastname: Sun
authors.forename: Zeguang
authors.initials: Z
authors.lastname: Wu
authors.forename: Hongfei
authors.initials: H
authors.lastname: Cheng
authors.forename: Zhanjun
authors.initials: Z
authors.lastname: Zhang
authors.forename: Ray L
authors.initials: RL
authors.lastname: Frost
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry*; D015394:Molecular Structure; D013055:Spectrophotometry, Infrared; D013059:Spectrum Analysis, Raman; D014732:Vibration
chemical_list: D002119:Calcium Carbonate; D008274:Magnesium; C028042:calcium magnesium carbonate
keywords: Calcite; Carbonate; Dolomite; Raman spectroscopy