Characterization of inorganic and biogenic magnesian calcites by Fourier Transform infrared spectroscopy

✍ Scribed by Michael E. Böttcher; Peer-Lennart Gehlken; D.Fraser Steele

• Book ID: 104296724
• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 450 KB
• Volume: 101-103
• Category: Article
• ISSN: 0167-2738
• DOI: 10.1016/s0167-2738(97)00235-x

✦ Synopsis

The effect of cationic substitution on the mid-infrared absorption spectra of synthetic, and natural inorganic and biogenic MgCO,-CaCO, solid solutions (Mg calcites; space group Rk; O-23 mol% MgCO,) is investigated, and the results are compared to disordered proto-dolomite (Ca,,,Mg, ,COs; space group Rk), ordered dolomite (Ca,,,Mg,,CO,; space group Rg), huntite (Ca,,,Mg 0.,$O,; space group R32), and magnesite (MgCO,; space group Rk). The measurements show that significant frequency shifts of the vibrational bands of the carbonate ion group occur as a function of chemical composition. The Mg2+ content of all Mg calcites correlates linearly with the position of the sharp u4 mode according to: v4 (cm-') = 39.40XM, + 712.20 (r = 0.97).