Crystallographic image processing (CIP) and high-resolution transmission electron microscopy (HRTEM) studies of bannisterite: a 2:1 type modulated layer silicate
Ferrow, Embaie A.; Hovmoller, Sven
European Journal of Mineralogy Volume 5 Number 1 (1993), p. 181 - 188
published: Mar 4, 1993
manuscript accepted: Oct 23, 1992
manuscript received: Feb 26, 1992
ArtNo. ESP147050501003, Price: 29.00 €
Abstract Two-dimensional crystallographic image processing (2D CIP) was performed on a high-resolution transmission electron microscopy (HRTEM) image of bannisterite from Broken Hill, Australia. Bannisterite is monoclinic and crystallizes in the A2/a space group with a = 2.29 nm, b = 1.64 nm, c = 2.46 nm, and ß = 94.36 degrees. HRTEM images were digitized with a CCD camera, and images processed on a personal computer using the program system CRISP. Crystallographic data was extracted from calculated Fourier transforms and processed giving an improved density map of the HRTEM image of bannisterite. Gross features and details such as pinching and swelling of the sinusoidal octahedral sheet, overlapping regular and inverted tetrahedra, and the column of large interlayer cations were easily discerned.