Low limit of Mn2+-activated cathodoluminescence of calcite: state of the art

✍ Scribed by Dirk Habermann; Rolf D. Neuser; Detlev K. Richter

• Book ID: 104167260
• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 927 KB
• Volume: 116
• Category: Article
• ISSN: 0037-0738
• DOI: 10.1016/s0037-0738(97)00118-8

✦ Synopsis

In the literature, the lower limit for Mn2+-activated cathodoluminescence (CL) of calcite is variously reputed to over a very wide range of values above 10 ppm Mn. Our spectroscopic investigations of the CL response in natural calcite reveal that below 10 ppm manganese content Mn2+ -activation is also present. Using the Quantitative High Resolution Spectral analysis of CL (QHRS-CL) an activation by Mn 2+ in the range of 700 ppb is proved, which cannot be determined visually. So, if not quenched, the minimum Mn2+ content for Mn'+-activation is one atom in the irradiated calcite crystal lattice volume. As the intrinsic (background blue) luminescence is used to determine non-altered biogenic calcite, the limit of Mn2+-activation plays .an important role in the interpretation of diagenetic processes. Our results of spectroscopic analyses require a revision of current opinions about the diagenesis of calcite as revealed by CL investigation.