Abstract
AbstractEudialyte-related compounds have been synthesised hydrothermally at T = 600°C and P = 2 kbar from a stoichiometric mixture of Na2CO3, CaO, Fe2O3, ZrOCl2 and SiO2 using the Na:Ca:Fe:Zr:Si ratios corresponding to the eudialyte end-member Na15Ca6Fe3Zr3Si(Si25O73)(OH)Cl2⋅H2O, in the presence of 1 M aqueous solutions of NaCl and NaF. The synthesis was carried out in platinum ampoules over 10 days. Natural raslakite (a Ca-deficient member of the eudialyte group) was used as a seed and added in amounts corresponding to 2 wt.% of the whole charge. The products were characterised by powder X-ray diffraction, IR and Raman spectroscopy, morphological features, and electron probe microanalyses. In experiments with NaCl, almost pure eudialyte-type compounds were obtained. Synthesis in the presence of a NaF solution resulted in the formation of a F-dominant eudialyte-type compound related to raslakite as the main product and aegirine, vlasovite and lalondeite as by-products. All synthesised eudialyte-type compounds are Zr-rich and Fe-deficient, similar to eudialyte-group minerals from hyperagpaitic rocks related to foyaites. The increased NaCl contents in the reaction system results in increased Ca content in the synthesised eudialyte-related compounds. The crystal-chemical formulae of the synthesised eudialyte-type compounds are derived based on general regularities established earlier for eudialyte-group minerals.
Subject
Geochemistry and Petrology
Reference20 articles.
1. Reproduction artificielle de quelques minéraux riches en zirconium (zircon, eudialyte, catapléite, elpidite) ; comparaison avec leurs conditions naturelles de formation
2. Ikranite, (Na,H3O)15(Ca,Mn,REE)6Fe3+2Zr3(□,Zr)(□,Si)Si24O66(O,OH)6Cl⋅nH2O, and raslakite, Na15Ca3Fe3(Na,Zr)3Zr3(Si,Nb)(Si25O73)(OH,H2O)3(Cl,OH), new eudialyte-group minerals from the Lovizero massif;Chukanov;Zapiski Rossiiskogo Mineralogicheskogo Obshchestva (Proceedings of the Russian Mineralogical Society),2003
3. THE NOMENCLATURE OF EUDIALYTE-GROUP MINERALS
4. New Data on the Isomorphism in Eudialyte-Group Minerals. 1. Crystal Chemistry of Eudialyte-Group Members with Na Incorporated into the Framework as a Marker of Hyperagpaitic Conditions
5. Identification of silicooxygen rings in SiO2 based on IR spectra
Cited by
2 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献