Crystal-chemical features of glauconite from Karinskoe deposit (South Urals)

Abstract

 ðàáîòå ïðåäñòàâëåíû ðåçóëüòàòû èçó÷åíèÿ ãëàóêîíèòà èç îòëîaeåíèé Êàðèíñêîãî ãëàóêîíèòîâîãî ìåñòîðîaeäåíèÿ. Âûäåëåííûå çåðíà áûëà èññëåäîâàíû êîìïëåêñîì ôèçèêî-õèìè÷åñêèõ ìåòîäîâ: ðåíòãåíîâñêîé äèôðàêòîìåòðèåé, ì¸ññáàóýðîâñêîé ñïåêòðîñêîïèåé 57 Fe, ñêàíèðóþùåé ýëåêòðîííîé ìèêðîñêîïèåé ñ ìèêðîïðîáíûì àíàëèçîì, Ôóðüå-ñïåêòðîñêîïèåé èíôðàêðàñíîãî ïîãëîùåíèÿ. Îñîáîå âíèìàíèå áûëî óäåëåíî êðèñòàëëîõèìè÷åñêèì îñîáåííîñòÿì ãëîáóëÿðíûõ ñëîèñòûõ ñèëèêàòîâ è ïðîöåññàì îáðàçîâàíèÿ ãëàóêîíèòà.Êëþ÷åâûå ñëîâà: ãëàóêîíèò, êðèñòàëëîõèìè÷åñêèå îñîáåííîñòè, çðåëîñòü ãëàóêîíèòà, ì¸ññáàóýðîâñêàÿ è ÈÊñïåêòðîñêîïèÿ, äèôðàêòîìåòðèÿ.The results of mineralogical investigation of glauconite from the Karinskoe deposit are presented. Grains were studied using complex of chemical and physical methods: X-ray diffraction, Mössbauer spectroscopy 57 Fe, scanning electron microscopy and microprobe analyses, Fourier-transform infrared spectroscopy.Special attention is given to the crystal-chemical features of mineral and processes of glauconite formation. Glauconite from the Karinskoe deposit is characterized by a relatively high content of K, Fe, Mg. Content of total iron and potassium display a direct correlation. According to Mössbauer and IR spectroscopy data Fe 2+ occupies not more than 10 % of the total iron content in glauconite. Crystal-chemical composition of mineral corresponds to «mature» glauconite, which was formed during the slow «maturing» of glauconite grains with increasing of the mica layers in its structure. Glauconite contains a small (10-15 %) amount of swelling layers. It can be proposed that smectite was a «precursor» for glauconite formation.

FTIR as a Method for Qualitative Assessment of Solid Samples in Geochemical Research: A Review

“…The authors recommended the dilution of soil samples using KBr (2-10% sample) [59]. Crystal-chemical features of glauconite were investigated by Simakova et al [60]. Before FTIR analysis, samples were prepared by pressing tablets, which contain 0.8 g KBr and some amount of the finely ground sample.…”

“…According to Simakova [60], who studied glauconite, highlighted that following the stretching band of (OH)-groups appears at 3534.4 cm −1 for the bonds Fe 3+ OHFe 3+ , at 3543.2 cm −1 for the bonds MgOHFe 2+ , at 3558.4 cm −1 for the bonds MgOHFe 3+ /or AlOHFe 2+ , at 3566.2 cm −1 for the bonds AlOHFe 3+ , at 3583.9 cm −1 for the bonds MgOHMg, at 3604.8 cm −1 for the bonds AlOHMg and, for the bonds AlOHAl, at 3619.0 and 3647.3 cm −1 . The bending deformation of the (Mg)Fe 3+ OHFe 3+ in the glauconite was observed at 818 cm −1 .…”

“…Glauconite absorbs at 1121, 1077, 1026, 992, and 957 cm −1 , which corresponds Si-O-Si stretching deformation at 914 cm −1 (stretching Si-O-Al), and at 460 cm −1 of the banding deformation Si-O-Si(Al) [54,60].…”