Palygorskite from Warren Quarry, Enderby, Leicestershire, England

Abstract

Specimens of palygorskite from Warren Quarry, Enderby, Leicestershire, have been studied in the laboratories. The mineral is found in dioritic rocks in association with angular dolomitic rock fragments as the filling material of a joint, the walls of which are sometimes lined with calcite and dolomite. Palygorskite occurs as 3-10 mm long bundles of fibres, 0·03-0·1μm wide. X-ray diffraction data indicate that the mineral may occur in the monoclinic form. The structural formula for the half-unit cell is Si8(Al1.89Fe0.053+Ti0.01Mg1.99)O20(OH)2(OH2)43·61 H2O.Ca0.07. Data obtained from differential thermal and infrared analyses are comparable with those for palygorskite in the literature, but the six-sided transversal cross-section of the fibres as revealed by electron microscopy is unexpected. The mineral was formed after the deposition of the overlying basal Triassic rocks when ground waters penetrated cracks in the dioritic rocks, causing Si and Mg to be released there and above the unconformity.

Palygorskite occurrence in northwest Nelson, South Island, New Zealand

“…3) of the three palygorskite samples show typical IR absorption bands at about 3625,3550, 3420, 3300,1670,1645,1190,1125,1093, 1040, 990, 940, 915, 732, 640, 582, 565, 515, 490, 450, and 420 cm" 1 , which are comparable with published spectra by Tien (1973), Otsuka et al (1968), and Van der Marel & Beutelspacher (1976). The IR spectrum of the Thomson Hill sample confirms the presence of small amounts of dolomite as an impurity.…”

Crystallochemical characterization of the palygorskite and sepiolite from the Allou Kagne deposit, Senegal

“…Pa1ygorskite is especia11y common in calcretes related to edaphic processes affecting sediments (Singer and Norrish, 1974;Watts, 1980;Singer, 1984;Verrecchia and Le Coustumer, 1996). Palygorskite and sepiolite can al so be formed as direct precipitates or as a replacement product from hydrothermal solutions (Tien, 1973;Haji-Vassilou and Puffer, 1975;López Galindo el al., 1996;Kamineni el al., 1993;Garcia-Romero el al., 2006). In general, Palygorskite is more abundant than sepiolite and although the two minerals sometimes appear together this is not often the case.…”

Effects of crystal chemistry on adsorption, occurrence, and mobility of water in palygorskite tunnels

“…As the zeolitic water can move in the tunnel and appear at different sites, the losing of zeolitic water is a continuous process. Many reported thermosgravimetric analysis and differential thermal analysis have revealed the sequence of dehydration as temperature increases (Artioli and Galli, 1994;Giustetto and Chiari, 2004;Hayashi et al, 1969;Kulbicki, 1959;Preisinger, 1963;Serna and Vanscoyoc, 1979;Tien, 1973;VanScoyoc et al, 1979). At 450 K, few zeolitic water could be left.…”