Abstract
Abstract Chiavennite (Mn endmember) and ferrochiavennite (Fe endmember) are beryllium silicate zeolites with chemical compositions close to Ca 1–2 (Mn,Fe)Si 5 Be 2 O 13 (OH) 2 ·2H 2 O. Five chiavennite crystals from four different localities, Chiavenna, Italy; Telemark, Norway; Uto, Sweden; and Ambatovita, Madagascar, were chosen for crystal-structure analysis. Initially all had been reported to be orthorhombic, but all are monoclinic, with a β angle near 90°, as is ferrochiavennite from Blafjell, Norway. Twinning on {100} is common. Chiavennite and ferrochiavennite are isostructural. The zeolite structure consists of intersecting channels of nine-, six-, five-, and four-fold rings. All five structures have one Ca site in common while chiavennite from Uto and ferrochiavennite from Blafjell have a second, partially filled, Ca site. Hydrogen atoms were located in all five structures. Hydrogen bonding is similar but not identical in all five structures. The H atoms associated with BeO 4 tetrahedra act as terminations to a polymerization sequence causing chiavennite and ferrochiavennite to be interrupted zeolite structures.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
