Halloysite Mineral Data

General Halloysite Information
Chemical Formula:	Al2Si2O5(OH)4
Composition:	Molecular Weight = 258.16 gm
	Aluminum 20.90 % Al 39.50 % Al₂O₃
	Silicon 21.76 % Si 46.55 % SiO₂
	Hydrogen 1.56 % H 13.96 % H₂O
	Oxygen 55.78 % O
	______ ______
	100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:	Al₂Si₂O₅(OH)₄
Environment:	A product of hydrothermal alteration or surface weathering of aluminosilicate minerals, as feldspars. Formed by dehydration of endellite above 110 deg. C.
IMA Status:	Valid Species (Pre-IMA) 1826
Locality:	Angleur, Li�ege, Belgium. Link to MinDat.org Location Data.
Name Origin:	Named after Baron Omalius d'Halloy (1707-1789).
Name Pronunciation:	Halloysite + Pronunciation
Synonym:	Endellite
	ICSD 26716
	PDF 29-1489
	halloysite-10 Ang.