Further Observations on the Morphology of Chrysotile and Halloysite

Abstract

Electron microscope studies of chrysotile show that tubes are present in bulk specimens and that these tubes commonly have fuzzy, amorphous-looking material on both the inside and outside. Similar material is associated with synthetic chrysotile and has been noted previously in halloysite specimens. The existence of such material between and within the tubes, together with apparent irregularities in size, shape and packing of tubes, explains the apparent discrepancy between the measured density of bulk samples and the calculated density of a hypothetical sample consisting of close-packed, regular, hollow capillaries. Replicas of fractured surfaces of halloysite (2H20) fl'om various localities reveal that the particles occur as curved to flat laths commonly possessing " hexagonal " terminations and surface features indicative of a higher degree of crystallinity than tubes of halloysite (4I~20). It is suggested that a complete morphological series from plates through laths to tubes exists both in platy to fibrous serpentine and in kaolinite to halloysite (4H~O). In each series a number of structural varieties are to be expected between the morphologically distinct " end members."

Study of microstructure of chrysotile asbestos by high-resolution electron microscopy

“…It is noted that the tilting of the two sets of the 4.5 A fringes are asymmetrical about the fibre axis with an angular difference of a few degrees. This type of growth pattern seems to correspond to the cone-in-cone pattern which was reported by Bates & Comer (1957).…”

“…In earlier X-ray studies, however, single crystals were not available, while in subsequent studies made on single crystals (individual fibrils), by means of electron microscopy combined with selected area electron diffraction, the instrumental resolution was not high enough to resolve the fine structures (Honjo & Mihama, 1954;Zussman, Brindley & Comer, 1957;Bates & Comer, 1957). Recently, it has become possible to observe lattice planes in the individual fibrils of chrysotile (FermindezMor~in, 1966;Yada, 1967), and it has been found, for example, that the circumferential lattice images observed in the cross-section of a fibril show a spiral or multi-spiral structure.…”

Globular Cluster Microstructure of Endellite (Hydrated Halloysite) from Bedford, Indiana

“…This complex was both stable under evacuation and tubular in morphology when examined by electron microscopy. Davis et al (1950), Taggart et al (1955, Bates and Comer (1959), and other workers have reported studies of dehydrated endellite preparations and in general concur that the particles observed are generally tubular. No particular mutual orientation of particles has been reported, although some flattening of the tubes was observed in a number of cases.…”

Quantitative theory of diffraction by cylindrical scroll nanotubes

“…Scroll nanotubes were discovered during electron microscopy studies of the naturally occurring minerals chrysotile and halloysite (Bates et al, 1950;Bates, 1957;Yada, 1967Yada, , 1971Yada & Iishi, 1977) in the 1950s. Later it was shown that a huge variety of scroll nanotubes with different chemical composition can be synthesized by various routes; up to now scroll nanotubes made of carbon (Bacon, 1960;Ruland et al, 2003;Shioyama & Akita, 2003;Chuvilin et al, 2009;Xie et al, 2009;Schaper, Hou et al, 2011), BN (Hwang & Suh, 2014), WS 2 (Li et al, 2002), TbS-CrS 2 (Panchakarla et al, 2016), SnS/ SnS 2 (Radovsky et al, 2011(Radovsky et al, , 2012, PbO (Shi et al, 2008), SrAl 2 O 4 (Ye et al, 2006), Ca 2 Nb 3 O 10 (Ma et al, 2004), K 4 Nb 6 O 17 (Saupe et al, 2000;Du et al, 2004;Tong et al, 2006;Adireddy et al, 2013), VO x (Krumeich et al, 1999;Muhr et al, 2000;Rostamzadeh et al, 2016), MnO 2 (Ma et al, 2004;Wang & Li, 2004), Mg 3 Si 2 O 5 (OH) 4 , Ni 3 Si 2 O 5 (OH) 4 (Krasilin & Gusarov, 2015;Krasilin et al, 2016Krasilin et al, , 2017 and Ruddlesden-Popper perovskites (Schaak & Mallouk, 2000) have been synthesized.…”