Surface microtopography of sudoite

Abstract

The gold-decoration technique of electron microscopy is used to study the surface microtopography of natural (001) surfaces of sudoite collected from a hydrothermal vein of the Berezovsk gold deposit, Central Urals, Russia. Only closed step patterns with malformed and/or nearly circular islands were observed on the (001) growth surface of sudoite crystals, implying a twodimensional nucleation mechanism. This is in contrast to the spiral step patterns commonly recognized on growth surfaces of other clay minerals, such as illite and kaolinite, formed under hydrothermal conditions. It is inferred that the crystallization of sudoite occurred under relatively higher temperatures and/or from more highly supersaturated fluids than many other hydrothermal clay minerals so far described.

High-resolution TEM and XRD simulation of stacking disorder in 2:1 phyllosilicates

“…Figures 6a-c show three representative HRTEM images of sudoite from Berezovsk, Urals, Russia (Drits and Lazarenko, 1967;Jige et al, 2003). The contrasts for most 2 : 1 layers indicate that the orientation of the 2 : 1 layer is uniform with the intralayer shift parallel (or anti-parallel) to the beam direction (see Kameda et al (2007) for the correspondence between experimental and simulated images).…”

Study of Low-Pressure Argon Adsorption on Synthetic Nontronite: Implications for Smectite Crystal Growth

“…This feature was consistent with the close-step pattern of two-dimensional growth, which led to an increase in the number of stacked layers. Such a growth pattern was observed for metamorphic mica (Sunagawa and Koshino, 1975) and hydrothermal sudoite (Jige et al, 2003). However, only two-dimensional crystal-growth processes occur during smectite formation.…”

“…Polygonal and/or broadly circular spiral-growth patterns have often been observed on the growth surfaces of biotite (Amelinks, 1952), phlogopite (Baronnet, 1972), illite (Inoue and Kitagawa, 1994;Kitagawa, 1998), rectorite (Kitagawa, 1997), kaolinite (Sunagawa and Koshino, 1975), and mixed-layer illite-smectite (Kitagawa and Matsuda, 1992). Two-dimensional nucleation was observed on the (001) growth surfaces of sudoite (Jige et al, 2003), which produced an increase in the number of stacked layers. The latter crystal-growth process is less commonly observed because a greater degree of fluid oversaturation is required.…”

AFM Study on Surface Microtopography, Morphology and Crystal Growth of Hydrothermal Illite in Izumiyama Pottery Stone from Arita, Saga Prefecture, Japan

“…After Frank [1] suggested the spiral growth mechanism to account for the growth of vapor-phase crystals, growth spirals with unit-cell-order step heights were observed on many mineral surfaces mainly by the following two methods, phase-contrast and interference contrast microscopy [2][3][4] and the platinum-carbon (PT-C) replica and golddecoration methods for transmission electron microscopy (TEM) [5][6][7][8][9][10][11]. These methods, however, do not permit to quantify surface microtopography on the unit-cell-order of minerals.…”