Mineralogy and chemistry of natrolite from Jordan
Author: Ibrahim, K.
Source: Clay Minerals, Volume 39, Number 1, 1 March 2004 , pp. 47-55(9)
Publisher: Mineralogical Society
Abstract:A natrolite-cemented palagonite ash tuff unit is reported in a palaeo-basin in northeast Jordan. Phillipsite and chabazite are also identified. The zeolites were formed due to transformation of volcanic glass granules into palagonite by the reaction with percolating water in a closed hydrological system. Consequently, Si, Al,Ca, Na and K are leached out and precipitated in a series of authigenic layers developed at the extreme edge of the granules. The recorded paragenetic sequence is smectite → phillipsite → chabazite → natrolite → analcime → calcite. The natrolite studied is chemically similar to those reported in the literature with minor variations. The phillipsite and chabazite studied are chemically different from the other Jordanian phillipsite and chabazite reported. The latter are chemically equivalent to those formed under open hydrological systems, whereas the phillipsite and chabazite in this study are chemically equivalent to those formed in saline lakes and arid soil environments. This conclusion is based on the (Na+K)/(Na+K+Ca+Mg) ratio and the Si/Al ratio.
Document Type: Research Article
Publication date: 1 March 2004