Hostname: page-component-797576ffbb-jhnrh Total loading time: 0 Render date: 2023-12-09T03:12:12.526Z Has data issue: false Feature Flags: { "corePageComponentGetUserInfoFromSharedSession": true, "coreDisableEcommerce": false, "useRatesEcommerce": true } hasContentIssue false

A rapid method for quantifying single mineral phases in heterogeneous natural dusts using X-ray diffraction

Published online by Cambridge University Press:  29 February 2012

Jennifer S. Le Blond*
Department of Geography, University of Cambridge, Downing Site, Cambridge CB2 3EN, United Kingdom and Department of Mineralogy, The Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom
Gordon Cressey
Department of Mineralogy, The Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom
Claire J. Horwell
Department of Earth Sciences, Science Laboratories, IHRR, Durham University, Durham DH1 3LE, United Kingdom
Ben J. Williamson
Camborne School of Mines, School of Geography, Archaeology & Earth Resources, University of Exeter, Penryn, Cornwall TR10 9EZ, United Kingdom
a)Author to whom correspondence should be addressed. Present address: Department of Geography, University of Cambridge, Downing Site, Cambridge CB2 3EN, UK. Electronic mail:


Quantification of potentially toxic single mineral phases in natural dusts of heterogeneous composition is critical for health hazard assessment. For example, crystalline silica, a human carcinogen, can be present as respirable particles in volcanic ash such as quartz, cristobalite, or tridymite. A method to rapidly identify the proportions of crystalline silica within mixed dust samples, such as volcanic ash, is therefore required for hazard managers to assess the potential risk of crystalline silica exposure to local populations. Here we present a rapid method for quantifying the proportions of single phases in the mineral assemblage of mixed dusts using X-ray diffraction (XRD) with a fixed curved position-sensitive detector. The method is a modified version of the whole-pattern peak-stripping (PS) method (devised by Cressey and Schofield [Powder Diffr.11, 35–39 (1996)]) using an internal attenuation standard (IAS) but, unlike the PS method, it requires no knowledge of other phases present in the sample. Ten synthetic sample mixtures were prepared from known combinations of four pure phases (cristobalite, hematite, labradorite, and obsidian), chosen to represent problematic constituents of volcanic ash, and analyzed by XRD. Results of the IAS method were directly compared with those of the PS method. The proportions of cristobalite estimated using the methods were comparable and accurate to within 3 wt %. The new IAS method involved less sample preparation and processing and, therefore, was faster than the original PS method. It therefore offers a highly accurate rapid technique for determination of the proportions of individual phases in mixed dusts.

Technical Articles
Copyright © Cambridge University Press 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)


Batchelder, M. and Cressey, G. (1998). “Rapid, accurate quantification of clay bearing samples by X-ray diffraction whole pattern stripping,” Clays Clay Miner. 46, 183194.Google Scholar
Beckett, W. S. (2000). “Occupational Respiratory Diseases,” N. Engl. J. Med.NEJMAG 342, 406413.Google Scholar
Cressey, G. (1999). “Recording X-ray snapshots of reaction kinetics: Clay hydration and cation exchange,” Microsource Application Note No. 8 ( Scholar
Cressey, G. and Schofield, P. F. (1996). “Rapid whole-pattern profile-stripping method for the quantification of multiphase samples,” Powder Diffr. 11, 3539.Google Scholar
Deer, W. A., Howie, R. A., and Zussman, J. (1992). An Introduction to the Rock Forming Minerals (Prentice Hall, New York), p. 696.Google Scholar
Hill, R. J. and Howard, C. J. (1987). “Quantitative phase analysis form neutron powder diffraction data using Rietveld method,” J. Appl. Crystallogr.JACGAR10.1107/S0021889887086199 20, 467474.Google Scholar
Horwell, C. J., Sparks, R. S. J., Brewer, T. S., Llewellin, E. W., and Williamson, B. J. (2003). “Characterization of respirable volcanic ash from the Soufrière Hills volcano, Montserrat, with implications for human health hazards,” Bull. Volcanol. (Heidelberg) 65, 346362.Google Scholar
Ibers, J. A. and Hamilton, W. C. (1974). International Tables for X-Ray Crystallography, Revised and Supplementary Tables to Volumes II and III (Kynoch, Birmingham), Vol. IV, pp. 12 and 366.Google Scholar
International Agency for Research on Cancer (IARC) (1997). Silica, Some Silicates, Coal Dust and Para-aramid Fibrils: IARC Monographs on the Evaluation of Carcinogenic Risks to Humans (IARC, Lyon, France), Vol. 68, p. 506.Google Scholar
Madsen, I. C. (1999). “Quantitative phase analysis round robin,” IUCR Newsl. 22, 3–5.Google Scholar
Madsen, I. C., Scarlett, N. V. Y., Cranswick, L. M. D., and Lwin, T. (2001). “Outcomes of the International Union of Crystallography commission on powder diffraction round robin on quantitative phase analysis: Samples 1a–1h,” J. Appl. Crystallogr.JACGAR10.1107/S0021889801007476 34, 409426.Google Scholar
Murphy, M. D., Sparks, R. S. J., Barclay, J., Carroll, M. R., and Brewer, T. S. (2000). “Remobilization of andesite magma by intrusion of mafic magma at the Soufrière Hills volcano, Montserrat, West Indies,” J. Petrol.JPTGAD 41, 2142.Google Scholar
Rodgers, K. A. and Cressey, G. (2001). “The occurrence, detection and significance of moganite (SiO2) among some silica sinters,” Miner. Mag.MNLMBB 65, 157167.Google Scholar
Schofield, P. F., Knight, K. S., Covey-Crump, S. J., Cressey, G., and Stretton, I. C. (2002). “Accurate quantification of the modal mineralogy of rocks when image analysis is difficult,” Miner. Mag.MNLMBB 66, 189200.Google Scholar
Sparks, R. S. J., Murphy, M. D., Lejeune, A. M., Watts, R. B., Barclay, J., and Young, S. R. (2000). “Control on the emplacement of the andesite lava dome of the Soufrière hills volcano, Montserrat by degassing-induced crystallization,” Terra Nova 12, 1420.Google Scholar
Talvitie, N. H. (1964). “Determination of free silica: Gravimetric and spectrophotometric procedures applicable to airborne and settled dust,” Am. Ind. Hyg. Assoc. J. 25, 169178.Google Scholar