Volume 26, Issue 1 (4-2018)                   www.ijcm.ir 2018, 26(1): 115-124 | Back to browse issues page


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Ghavi, Karimpour, Pan, Mazaheri. The emersion and crystallography of erythrite (Co3(AsO4)28H2O), discovered in Tarikdarreh area, NE Iran. www.ijcm.ir. 2018; 26 (1) :115-124
URL: http://ijcm.ir/article-1-1054-en.html
Abstract:   (613 Views)
Erythrite (Co3 (AsO4)28H2O) is one of the rare arsenic minerals which belong to the vivianite group. A recent discovery in Tarikdarreh prospect area (northeastern Iran) found erythrite along with scorodite and hydroxides of iron have been recognized as a supergene alteration product of primary arsenic mineral in surface arsenopyrite ± pyrite mineralization veins zones. A specimen of erythrite has pale red to shiny pink color and aggregates to form into a bright red color star with a radial structure. When observed under a microscope it is elongated in C crystal axial with pleochroism. This mineral has a monoclinic system, space group C2/m and the unit-cell parameter constants are a = 10.251, b = 13.447, c = 4.764, β = 104.98. The crystalline structure of this mineral forms chains of tetrahedral of arsenic, octahedra of cobalt-iron which bind with oxygen and hydrogen. Scanning electron microscope images of this crystal exhibit a timber shape and SEM-EDX analysis have confirmed As, Co elements in this crystal structure and chemical composition. An XRD examination reveals arsenopyrite as the main sulphide phase in the mineralization zone and analysis by ICP-Mass have shown that they have high levels of cobalt element. Surface weathering of arsenopyrite has provided aqueous species of cobalt and arsenide for crystallization erythrite. On the other hand erythrite can only be stable in the range of 6 to 8 pH conditions, and then Eh-pH condition has an important role in controlling the stability and solubility of erythrite.
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Type of Study: Research | Subject: Special
Received: 2018/02/28 | Accepted: 2018/02/28 | Published: 2018/02/28

References
1. [1] Williams G. j., "Note on the mineralization in Cheshmegool area, khorasan", Geology Survey of Iran, (1965) 3 p.
2. [2] Khakzad A., Karimpour M. H., Yazdi M., Shafi Niya H., "Heavy minerals studies and their relationship with Gold mineralization in of Tarik Darreh area", 10st Symposium of Crystallography and Mineralogy of Iran, Zahedan (2002) 116-117 (abstract in Farsi).
3. [3] Ghavi J., Karimpour M. H., Mazaheri S. A., Ghaderi M., Rahimi B., "Identifying secondary dispersion halos and geochemical element distribution in soils on the Tarik Darreh Au-W prospect area, north of Torbat-e-Jam, NE Iran", Iranian Journal of Crystallography and Mineralogy 21 Issue 1 (2013) 107-120 (in Farsi with English abstract).
4. [4] Ghasemzadeh F., Malekzadeh Shafaroudi A., "Environmental effect of arsenic in Cheshmeh-Zard area, southwest of Nyshabour, Khorasan Razavi Province", Iranian Journal of Crystallography and Mineralogy 19, Issue 3 (2011) 545-556 (in Farsi with English abstract).
5. [5] Ghavi J., Karimpour M. H., Mazaheri S. A., "Preliminary Data Of Erythrite (Co3(AsO4) 28H2O), Rare Arsenate Minerals From Tarikdarreh Au-W Prospect Area, NE Iran", 5st conference of Iranian Society of Economic Geology, Mashhad (2012) 9-11 (abstract in Farsi and English).
6. [6] Boulin J., "Structures in Southwest Asia and evolution of the eastern Tethys", Tectonophysics 196 Issues 3-4 (1991) 211-268. [DOI:10.1016/0040-1951(91)90325-M]
7. [7] Rutner A., "The Triassic of Agh darband", Scientific Quarternry Journal Geosciences 27-28 (1991) 87-95.
8. [8] Morimoto N., Clakk A.L., "Arsenopyrite crystal-chemical relations", American Mineralogist, 46 (1961) 1539-1552.
9. [9] Drahota P., Filippi M., "Secondary arsenic minerals in the environment", A review Environment International 35 (2009) 1243–1255. [DOI:10.1016/j.envint.2009.07.004]
10. [10] http://www.mindat.org/min-8868.html
11. [11] Cook R.B., "Erythrite, Bou Azzer, Morocco", Rocks & Minerals Journal,Volume 82 (2007) 402-407. [DOI:10.3200/RMIN.82.5.402-408]
12. [12] Barth T.F.W., "Crystallographic studies n the vivianite group", Amarican Mineralogy (1937), 22, 325.
13. [13] Cooper M.A., Hawthorne F.C., "The Crystal Structure Of Burgessite, Co2 (H2O)4 [AsO3(OH)]2 (H2O), and its relation to erythrite", The Canadian Mineralogist, Vol. 47 (2009) 165-172 . [DOI:10.3749/canmin.47.1.165]
14. [14] Faye G.H., Nickelt E.H., "The origin of pleochroisimn erythrite", the Canadian mineralogist (1968) 493-504.
15. [15] Jambor J., Dutrtzac J., "Solids solution in the annabergit-erythrite-Hornesite senthenc system", the Canadian Mineralogist, 33 (1995) 1063-1071.
16. [16] Komnitsas K., Xenidis A., Adam K., "Oxidation of pyrite and Arsenopyrite in sulphidid spoils in Lavrion", Minerals Engineering, Vol. 8.No.12. (1995) 1443–1454. [DOI:10.1016/0892-6875(95)00109-3]
17. [17] Craw D., Falconer D., Youngson J.H., "Environmental arsenopyrite stability and dissolution: theory, experiment, and field observations", Chemical Geology, Vol. 199 (2003) 71-82. [DOI:10.1016/S0009-2541(03)00117-7]
18. [18] Dow P.M, Rimested D., "The solubility and stability of scorodite, FeAsO4.2H2O", American Mineralogist, 70 (1985) 838-844.
19. [19] Lu P., Zhu C., "Arsenic Eh–pH diagrams at 25_C and 1 bar", Environ Earth Sci. Vol 62. 2011, 1673-1683. [DOI:10.1007/s12665-010-0652-x]
20. [20] Takeno N., "Intercomparison of thermodynamic databases", National Institute of Advanced Industrial Science and Technology Research Center for Deep Geological Environments. 2005 287p.
21. [21] Ahmed A, H., Arai Sh., Ikenne M., "Mineralogy and Paragenesis of the Co-Ni Arsenide Ores of Bou Azzer, Anti-Atlas, Morocco", Economic Geology v. 104; no. 2 (2009) 249-266. [DOI:10.2113/gsecongeo.104.2.249]
22. [22] Markl G., Marks M.A.W., Derrey I., "Weathering of cobalt arsenides: Natural assemblages and calculated stability relations among secondary Ca-Mg-Co arsenates and carbonates", American Mineralogist. Volume 99, Issue 1(2014) 44–56 [DOI:10.2138/am.2014.4540]

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