Identification of biogenetic calcite and aragonite using SEM

Bermanec, Vladimir and Posilović, Hrvoje and Žigovečki Gobac, Željka (2009) Identification of biogenetic calcite and aragonite using SEM. Geologia Croatica, 62 (3). pp. 201-206.

[img] PDF
Restricted to Registered users only
Language: English

Download (567kB)

Abstract

Identifi cation of calcite and aragonite is very important for studying different fossil or recent biomineralized skeletons. A problem occurs when scanning electron microscopy is used for studying calcite and aragonite present in the same part of skeleton. The same chemical composition of these two minerals produces the same contrast on SEM images. There are three possible ways to distinguish calcite and aragonite in such a mixture. (1) It is possible to recognize the crystal habits of these two minerals, if crystal faces are developed. (2) The geochemical difference can also be an important tool for distinguishing aragonite (containing large cations like Sr, Ba, or Pb) from calcite (containing small cations like Mg, Mn, Fe, Zn, or Ni). However, it is also possible that large cations remain in the calcite crystal structure after phase transformation from aragonite to calcite. (3) The third possibility for distinguishing calcite from aragonite is to use staining methods. Different staining methods used for SEM analyses have had varying degrees of success. SUZUKI et al. (1993) successfully used Meigen’s staining method, but results provided by Feigl’s staining method were unsatisfactory. The failure when using Feigl’s staining method was caused by the erroneous application of the solutions.

Item Type: Article
Keywords: Calcite, aragonite, morphology, geochemical difference, Feigl’s staining method, SEM
Date: 2009
Subjects: NATURAL SCIENCES > Geology > Mineralogy and Petrology
Divisions: Faculty of Science > Department of Geology
Publisher: Hrvatsko geološko društvo
Depositing User: Danica Vujičić
Date Deposited: 02 Jul 2015 09:55
Last Modified: 02 Jul 2015 09:55
URI: http://digre.pmf.unizg.hr/id/eprint/3685

Actions (login required)

View Item View Item