Near Infrared Spectroscopy of Marble from Chillagoe,Australia and in Comparison with other Selected Natural Carbonates

Marble from the Chillagoe deposits was extensively used in the construction of Australia's parliament house. Near infrared (NIR) spectroscopy has been applied to study the quality of marble from the Chillagoe marble deposits and to distinguish between different types of marble in the Chillagoe deposits. A comparison of the NIR spectra of marble with dolomite and monohydrocalcite is made. The spectrum of the marble closely resembles that of monohydrocalcite and is different from that of dolomite. The infrared spectra of the minerals are characterised by OH and water stretching vibrations. Both the first and second fundamental overtones of these bands are observed in the NIR spectra. Marble is characterised by NIR bands at 4005 cm⁻¹, 4268 cm⁻¹ and 4340 cm⁻¹, attributed to carbonate combination bands and overtones. Marble also shows NIR bands at 5005 cm⁻¹, 5106 cm⁻¹, 5234 cm⁻¹ and 5334 cm⁻¹ assigned to water combination bands. Finally, the NIR spectrum of the marble displays broad low-intensity features centred upon 6905 cm⁻¹ attributed to the water first overtones. It appears feasible to identify marble through the use of NIR spectroscopy.