Pressure-induced Hydration in Zeolite Tetranatrolite

Journal Article · Sun Jan 01 04:00:00 EST 2006 · Am. Mineral.

DOI:https://doi.org/10.2138/am.2006.1847· OSTI ID:914043

Lee, Y; Hriljac, J; Parise, J; Vogt, T

The tetranatrolite-paranatrolite transformation has remained a key problem in understanding the paragenesis of zeolites in the natrolite family. It is accepted that when paranatrolite, approximate formula Na{sub 16-x}Ca{sub x}Al{sub 16+x}Si{sub 24-x}O{sub 80}{center_dot}24H{sub 2}O, is removed from an aqueous environment and exposed to the atmosphere, it loses water and transforms to tetranatrolite, Na{sub 16-x}Ca{sub x}Al{sub 16+x}Si{sub 24-x}O{sub 80}{center_dot}nH{sub 2}O (n {le} 24). Here we show that this transformation is not only reversible, but that tetranatrolite exhibits two sequential pressure-induced hydrations leading first to paranatrolite and then to a superhydrated tetranatrolite above 0.2 and 3.0 GPa, respectively. We have previously reported similar behavior for the corresponding system with an ordered Si/Al distribution, i.e., natrolite itself, however the ordered version of paranatrolite exists over a much smaller pressure range. The pressure-induced transformations of natrolite and tetranatrolite thus further supports the supposition that paranatrolite is a distinct mineral species, with a pressure-stability field dependent upon composition.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 914043
• Report Number(s): BNL--78611-2007-JA
• Journal Information: Am. Mineral., Journal Name: Am. Mineral. Vol. 91; ISSN AMMIAY; ISSN 0003-004X
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
DISTRIBUTION
HYDRATION
NSLS
PRESSURE RANGE
TRANSFORMATIONS
WATER
ZEOLITES
national synchrotron light source