Source: http://iuggu.ru/en/archive/2017/4-17/81-en/805-9-4-17
Timestamp: 2019-04-19 07:23:01+00:00

Document:
The author developed the technique of electron-probe microanalysis for quantitative determination of beryllium content, providing the example of studying natural minerals (aluminosilicates and oxides). This technique allowed to obtain a quantitative content of beryllium (in combination with other elements) in the emeralds of the Mariinsky beryllium deposit and in zonal mariinskite-chrysoberyl from the chromitites of the Bazhenov ophiolite complex. All analyzes of minerals were performed on a CAMECA SX 100 electron probe microanalyzer with five wave spectrometers (IGG UB RAS). The pressure in the sample chamber was 2 × 10–4 Pa, in the electron gun region – 4 × 10–6 Pa, in wave spectrometers – 7 Pa. Accelerating voltage was 10 kV, the current of absorbed electrons on the Faraday cylinder (beam current) was 100–150 nA. Diameter of the electron beam focused on the sample was 2 μm, the angle of x-ray extraction was 40°. The spectra were obtained on wave spectrometers with TAP crystal analyzers (2d = 25.745 Å), LPET (2d = 8.75 Å), LiF (2d = 4.0226 Å), and PC3 (2d = 211.4 Å, a specialized crystal for determining the content of beryllium and boron); the author carried out all the elements measurements along the Kα-lines. To determine position of the analytical peak and the background from two sides with the minimum possible spectral overlap, the author preliminarily recorded spectra on wave spectrometers. The obtained microprobe analyzes of minerals with quantitative determination of beryllium converge well with the available theoretical compositions of beryl and chrysoberyl, which indicates the high efficiency of the developed technique. By using this technique, we can relatively quickly and reliably determine the quantitative content of beryllium in natural silicates and oxides, which is an acute need for geological researchers studying the mineralogy of beryllium deposits.
Keywords: beryllium; chrysoberyl; mariinskite; beryl; emerald; electron-probe microanalysis.
1. Lavrent’ev Yu. G., Karmanova N. G. 2012, Sed’maya Vserossiyskaya konferentsiya po rentgenospektral’nomu analizu [Seventh All-Russian Conference on X-ray Spectroscopy]. Zhurnal analiticheskoy khimii [Journal of Analytical Chemistry], vol. 67, no. 6, pp. 669–671.
2. Aleksandrov S. M., Troneva M. A. 2011, Elektronno-zondovyy mikroanaliz endogennykh boratov margantsa iz skarnovykh mestorozhdeniy Yaponii [Electron probe microanalysis of endogenous manganese borates from Japanese skarn deposits]. VII Vserossiyskaya konferentsiya po rentgenospektral’nomu analizu. Tezisy dokladov [All-Russian Conference on X-ray Spectroscopy. Theses of reports], Novosibirsk, p. 47.
3. Raudsepp M. 1995, Recent advances in the electron-probe microanalysis of minerals for the light elements. Canadian Mineralogist, vol. 33, pp. 203–218.
4. Viryus A. A. 2010, Lokal’nyy rentgenospektral’nyy analiz geologicheskikh ob'ektov [Local X-ray spectral analysis of geological objects]. Materialy VI Mezhdunarodnoy Shkoly po Naukam o Zemle imeni professora L. L. Perchuka [Materials of the International School for Earth Sciences named after prof. Perchuk L. L.], Odessa, p. 29–31.
5. Kulikova I. M. 1995, Rentgenospektral’nyy mikrozondovyy analiz soderzhaniya bora v razlichnykh mineralakh. Metodicheskie rekomendatsii. VIMS [X-ray spectral microprobe analysis of boron content in various minerals. Guidelines. All-Russian Institute of Mineral Raw Materials], Moscow, 18 p.
6. Troneva M. A., Kononkova N. N., Aleksandrov S. M. 2006, Rentgenospektral’nyy analiz boratov na primere lyudvigitov i vonsenitov [X-ray spectral analysis of borates on the example of ludwigites and vonsenites]. Tezisy dokladov V Vserossiyskoy konferentsii po rentgenospektral’nomu analizu [Abstracts of the All-Russian Conference on X-ray Spectroscopy], Irkutsk, 80.
7. Groat L. A., Giuliani G., Marshall D. D., Turner D. 2008, Emerald deposits and occurrences: A review. Ore Geology Reviews, vol. 34, pp. 87–112.
8. Grice J. D., Rowe R., Poirier G. 2009, Bussyite-(Ce), a new beryllium silicate mineral species from Mont Saint-Hilaire, Quebec. Canadian Mineralogist, vol. 47, pp. 193–204.
9. Pekov I. V., Zubkova N. V., Chukanov N. V., Agakhanov A. A., Belakovskiy D. I., Horvath L., Filinchuk Ya. E., Gobechiya E. R., Pushcharovsky D. Yu., Rabadanov M. K. 2008, Niveolanite, the first natural beryllium carbonate, a new mineral species from Mont Saint-Hilaire, Quebec, Canada. Canadian Mineralogist, vol. 46, pp. 1343–1354.
10. Artioli G., Rinaldi R., Stahl K., Zanazzi P. F. 1993, Structure refinements of beryl by single-crystal neutron and X-ray diffraction. American Mineralogist, vol. 78, pp. 762–768.
11. Pautov L. A., Popov M. P., Erokhin Yu. V., Khiller V. V., Karpenko V. Yu. 2013, Mariinskite, BeCr2O4, a new mineral, chromium analog of chrysoberyl. Geology of Ore Deposits, vol. 55, no. 8, pp. 648–662.
12. Erokhin Yu. V., Khiller V. V., Zoloev K. K., Popov M. P., Grigor’ev V. V. 2014, Mariinskite from the Bazhenovskii ophiolite complex: the second finds in the World. Doklady Earth Sciences, vol. 455, part 2, pp. 408–410.
13. Khiller V. V., Erokhin Yu. V. 2011, Mikrozondovoe opredelenie berilliya v mineralakh ryada BeAl2O4–BeCr2O4 [Microprobe determination of beryllium in minerals of the series BeAl2O4–BeCr2O4]. VII Vserossiyskaya konferentsiya po rentgenospektral’nomu analizu. Tezisy dokladov [All-Russian Conference on X-ray Spectroscopy. Theses of reports], Novosibirsk, p. 80.
14. Khiller V. V., Erokhin Yu. V. 2012, Opredelenie soderzhaniya berilliya metodom rentgeno-spektral’nogo elektronno-zondovogo mikroanaliza [Determination of beryllium content by X-ray spectral electron probe microanalysis]. Materialy Vserossiyskoy konferentsii po analiticheskoy spektroskopii [Materials of the All-Russian Conference on Analytical Spectroscopy], Krasnodar, pp. 175.

References: V. 
 V. 
 V. 
 V. 
 V. 
 V. 
 V. 
 V.