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Title: The use of the scanning electron microscope in the determination of the mineral composition of Ballachulish slate

Journal Article · · Materials Characterization
 [1]
  1. University of Paisley, Scotland (United Kingdom), E-mail: ja_walsh@tiscali.co.uk

Slate is a fine-grained, low-grade metamorphic rock derived from argillaceous sediments or occasionally volcanic ash. Although most slates contain mainly quartz, chlorite and white mica, they vary considerably in their durability, some lasting centuries while others fail after a few years of service. A detailed characterisation of their mineralogy is required for the assessment of performance, and to establish the provenance of a used slate. A combination of methods was used to examine Ballachulish slates; XRD analysis to determine the principal minerals present, XRF analysis to determine the total chemical composition, and scanning electron microscopy to determine the chemical composition of individual minerals. It was found that the white mica in Ballachulish slate is phengite and the chlorite is ripidolite. Feldspar is present as albite and carbonate as ferroan dolomite. Several accessory minerals were also identified, including chloritoid, monzonite and zircon. There was considerable variation in the ratio of the principal minerals, making it impossible to identify used slates by this criterion. Instead, chemical composition of the individual minerals, and possibly key accessory minerals, should be used to determine the provenance of slates.

OSTI ID:
21062171
Journal Information:
Materials Characterization, Vol. 58, Issue 11-12; Conference: 10. Euroseminar on microscopy applied to building materials (EMABM), Paisley, Scotland (United Kingdom), 21-24 Jun 2005; Other Information: DOI: 10.1016/j.matchar.2007.04.013; PII: S1044-5803(07)00157-X; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 1044-5803
Country of Publication:
United States
Language:
English