Artificial Alteration of Biotite into a 14 Å Layer Silicate with Hydroxy-Aluminium Interlayers

K. Nagasawa
1974 Clays and clay minerals  
Biotite was altered by boiling in 0.2 M AIC13 solution, and the products were examined by X-ray powder and single-crystal diffraction, chemical analysis and thermogravimetry. The altered material is a 14 A clay mineral with hydroxy-Al interlayers. It has a stacking sequence characteristic 9 of vermiculite and its silicate layers are similar in chemical composition to trioctahedral vermiculite. The results of extracting the interlayer material with sodium citrate sol_ution,' X-ray examinations
more » ... ter heating and thermogravimetry show that the interlayer material is composed of A1 associated with OH and H20. The chemistry and kinetics of the alteration reaction and the orientational betv~een the altered and original biotites are also discussed.
doi:10.1346/ccmn.1974.0220306 fatcat:nc5waor5nrbwzgc3ummvhlpuwe