Ferric iron content of mineral inclusions in diamonds from Sao Luiz: A view into the lower mantle

Science

Volumn 278, Issue 5337, 1997, Pages 434-436

  McCammon, Catherine ^a   Hutchison, Mark ^b   Harris, Jeff ^c  

^a UNIVERSITÄT BAYREUTH   (Germany)

^b UNIVERSITY OF EDINBURGH   (United Kingdom)

^c UNIVERSITY OF GLASGOW   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

DIAMOND; FERRIC ION; MINERAL;

DIAMOND; IRON; MANTLE (LOWER); MINERAL INCLUSION; MOSSBAUER SPECTROSCOPY;

BRAZIL; CHEMICAL COMPOSITION; CHEMISTRY; GEOLOGY; PRIORITY JOURNAL; REVIEW; SPECTROSCOPY;

EID: 0030667978     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.278.5337.434     Document Type: Review

References (29)

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6. 2). The gamma rays are collimated to the selected sample diameter using a Pb shield, and the source-sample distance is reduced to <5 mm. The latter results in a solid angle similar to conventional experiments, and hence a similar count rate. Because the signal quality depends on absorber density (measured in milligrams of Fe per square centimeter) and not the total amount of iron in the sample, the reduction in sample size has no effect on the effective thickness of the absorber. When electronic absorption due to heavier elements is low and the point source is relatively new (<1 year old), high-quality Mössbauer spectra (comparable to conventional measurements) can be recorded on samples with diameters as small as 100 μm. For further information see C. A. McCammon, V. Chaskar, and G. G. Richards [Meas. Sci. Technol. 2, 657 (1991)] and C. A. McCammon [Hyper. Int. 92, 1235 (1994)].
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29. The mineral inclusions were supplied by B. Harte, and the electron microprobe analyses for samples BZ66, BZ67, BZ73, and BZ210B were performed by M. Wilding and B. Harte. The manuscript was improved through discussions with B. Harte and S. Kesson.