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Study of Natural Halloysite from the Dragon Mine, Utah (USA)
Author(s) -
García Francisco J.,
García Rodríguez Sergio,
Kalytta Andreas,
Reller Armin
Publication year - 2009
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.200900076
Subject(s) - halloysite , platy , mineralogy , alunite , geology , materials science , chemical engineering , geochemistry , composite material , hydrothermal circulation , paleontology , engineering
A natural sample from the Dragon Mine, Tintic District, Silver City, Utah (USA), has been characterised. It contains a mixture of halloysite and alunite. The former shows the characteristic tubularly shaped particles while the latter is found to crystallise in platy particles. The crystal structure of halloysite is stable up to 400–450 °C and before decomposition some crystallisation is observed. Amorphisation is observed with further increasing the annealing temperature. However, the halloysite particles conserve the original morphology (tubes) up to 900 °C. The size distribution of the tubes is found to be quite broad. This is argued to be responsible for the poor measured surface area.