Discovery of volkonskoite

Abstract

All three polymorphs exhibit a single broad asymmetric band at 140 cm-1 (not shown), the assignment of which is not known.Conclusions. The variation in spectra described here for the three polymorphs differs from that described previously for various specimens of leadhillite (sensu strictu) by Russell et al. (1983) who showed that the relative intensity of OH, CO3, and SOn absorption bands varied, and proposed that mutual substitution of these ions occurs within the leadhillite structure.The X-ray powder pattern of macphersonite is distinctly different from those of susannite and leadhillite (Livingstone and Sarp, 1984), which themselves, as reported by Mrose and Christian (1969), are virtually indistinguishable. It is shown here, however, that all three polymorphs are readily distinguished by their IR spectra. Moreover, the appearance in a high resolution IR spectrum of the closely spaced 691, 687 cm-~ doublet may be diagnostic for macphersonite.

On the structural formula of smectites: a review and new data on the influence of exchangeable cations

“…Stevensite is a trioctahedral Mg-rich smectite with minor or without tetrahedral substitutions, having a deficit of cations in the octahedral sheet that leads to a low negative layer charge. Other species that have been described for the smectite group according to their crystallochemistry and structural formula are hectorite and swinefordite, which are trioctahedral smectites with Li + as the octahedral cation, volkonskoite, which is dioctahedral and Cr 3+ rich (Mackenzie, 1984;Khoury & Al-Zoubi, 2014), and rare ones such as sauconite, which is a dioctahedral Znbearing smectite (Ross, 1946;Balassone et al, 2017). Newman & Brown (1987) compiled eight structural formulae of saponite with excess octahedral charge, and affirmed that 'The net negative charge on the layers derives from Al for Si substitution in the tetrahedral sites, but this is partially compensated by substitution of trivalent cations into the octahedral sites.'…”

Reassessment of the Volkonskoite-Chromian Smectite Nomenclature Problem

“…Although Mackenzie (1984a) correctly observed that most standard texts attribute the first description of the mineral volkonskoite to K~mmerer (1831) and noted that the mineral was first described in 1830, some important in-formation may be added. Krotov (1902) acknowledged that volkonskoite was discovered in 1830, and Kryzhanovski (1928) cited several references that made mention of this fact.…”

“…Krotov (1902) acknowledged that volkonskoite was discovered in 1830, and Kryzhanovski (1928) cited several references that made mention of this fact. Aleksandrov et al (1940) described a first period of investigation of volkonskoite from 1830 to 1850 and quoted an anonymous article from the 1830 Gornyi Zhurnal that was also mentioned by Mackenzie (1984a). Borisenko and Borisenko (1962) stated that "Despite the fact that the first reference to volkonskoite, published in the Gornyi Zhurnal, dates to the year 1830, to the present time there remains a series of controversial questions linked with the mineralogy and genesis of this mineral."…”

“…The anonymous report in 1830 (quoted in Aleksandrovet al, 1940;Borisenko and Borisenko, 1962;and Mackenzie, 1984a) gave the type locality of volkonskoite as Mount Efimyata (see, e.g., Kokscharov, 1853) near the village of Efimyata (see Aleksandrov et al, 1940) in the Okhansk district, middle Kama River area, west of Perm, on the west side of the Ural Mountains. I~mmerer (1831) noted the occurrence of the mineral, but the first complete analysis appears to have been made by Berthier in 1833 (see Kersten, 1839).…”

“…History of the nomenclature problem Khoury et al (1984) and particularly Mackenzie (1984aMackenzie ( , 1985 discussed the early history of the discovery and characterization of volkonskoite from the Okhansk region, in the Soviet Union. Although Mackenzie (1984a) correctly observed that most standard texts attribute the first description of the mineral volkonskoite to K~mmerer (1831) and noted that the mineral was first described in 1830, some important in-formation may be added.…”