Skip to main content

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

  • Jennifer S. Le Blond (a1), Gordon Cressey (a2), Claire J. Horwell (a3) and Ben J. Williamson (a4)

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.

Corresponding author
a)Author to whom correspondence should be addressed. Present address: Department of Geography, University of Cambridge, Downing Site, Cambridge CB2 3EN, UK. Electronic mail:
Hide All
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.
Beckett, W. S. (2000). “Occupational Respiratory Diseases,” N. Engl. J. Med.NEJMAG 342, 406413.
Cressey, G. (1999). “Recording X-ray snapshots of reaction kinetics: Clay hydration and cation exchange,” Microsource Application Note No. 8 (
Cressey, G. and Schofield, P. F. (1996). “Rapid whole-pattern profile-stripping method for the quantification of multiphase samples,” Powder Diffr. 11, 3539.
Deer, W. A., Howie, R. A., and Zussman, J. (1992). An Introduction to the Rock Forming Minerals (Prentice Hall, New York), p. 696.
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.
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.
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.
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.
Madsen, I. C. (1999). “Quantitative phase analysis round robin,” IUCR Newsl. 22, 3–5.
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.
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.
Rodgers, K. A. and Cressey, G. (2001). “The occurrence, detection and significance of moganite (SiO2) among some silica sinters,” Miner. Mag.MNLMBB 65, 157167.
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.
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.
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.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Powder Diffraction
  • ISSN: 0885-7156
  • EISSN: 1945-7413
  • URL: /core/journals/powder-diffraction
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed