The origin of spheroidal halloysites: a review of the literature

CRAVERO F.; CHURCHMAN G. JOCK

CLAY MINERALS (PRINT)

MINERALOGICAL SOC

Lugar: Middlesex; Año: 2016 vol. 51 p. 417 - 427

0009-8558

Tubular halloysite has many applications as a nanomaterial. Spheroidal halloysite(SPH)istheothermostcommonformofhalloysite.Itsmodeofformationhashaddifferentexplanations, including association with allophane, or more generally, following weathering of volcanic glass. Some SPHshaveformedfrommineralsincrystallinerocks,sometimesasanearlystageofevolutionintoplates and/or tubes of halloysite and ultimately to kaolinite. Spheroidal halloysites can show a range of Fe contents and can occur with other forms of halloysite; they have often formed in confined environments whereas tubular halloysites apparently form in more opens paces.They have also formed on microbes or where there is a significant amount of organic matter. Generally, SPHs have often formed by rapid dissolution of volcanic glass and primary minerals. TheSPHscanpersistovertime.Theyhavefewactive edges, so interparticle interaction is poor, causing low viscosities in clay-water suspensions, poor soil stability and low adsorption capacities.