Mineral Liberation Analysis and Scanning Electron Microscopy of Connemara Marble: New Mineral Distribution Maps of an Iconic Irish Gem Material

• Published in: Journal of gemmology (1986) Vol. 36; no. 5; pp. 456 - 466
• Main Authors: Feely, Martin, Wilton, Derek H., Costanzo, Alessandra, Kollar, Albert D., Goudie, Dylan J., Joyce, Ambrose
• Format: Journal Article
• Language: English
• Published: London Gem-A, The Gemmological Association of Great Britain 01.01.2019; The Gemmological Association of Great Britain
• Subjects: Color; Distribution; Electron microscopy; Gemology; Identification and classification; Marble; Mineralogy; Properties; Scanning electron microscopy; Ireland
• ISSN: 1355-4565; 2632-1718
• DOI: 10.15506/JoG.2019.36.5.456

This article reports results from mineral liberation analysis-scanning electron microscopy (MLA-SEM) of six samples of the iconic Irish gem material, Connemara marble. New false-colour mineral distribution maps along with quantitative mineral abundance data for each sample facilitate correlations between marble mineralogy and millimetre- to centimetre-scale colour variations in banding observed in each sample. The modal mineral data were used to classify each of the samples, and indicate that they define a petrological continuum from calc-silicate to metacarbonate rocks. The results demonstrate the efficacy of MLA-SEM methodology for generating mineral distribution maps along with quantitative modal analysis that inform and enhance the study of inhomogeneous gem materials such as the Connemara marble. Finally, this study demonstrates the potential for MLA-SEM analyses to aid in the fingerprinting and authentication of other polymineralic gems akin to Connemara marble.