Johnston, Cliff T.Cliff T.JohnstonSHAN-LI WANGBish, David L.David L.BishDera, PrzemyslawPrzemyslawDeraAgnew, Stephen F.Stephen F.AgnewKenney III., John W.John W.Kenney III.2018-09-102018-09-102002-08-15https://www.scopus.com/pages/publications/0037104932?origin=resultslistHigh-pressure Raman and X-ray diffraction data on single crystals of hydrous layer-structure minerals, dickite and gibbsite, reveal structural phase transitions occuring between 2.0 and 2.5 GPa. In the case of dickite, this is the first documented occurence of a pressure-induced phase transformation in a 1:1 phyllosilicate. Above the transition the structure of individual 1:1 layers remains unchanged, whereas the stacking of individual layers and the interlayer topology change significantly. Similar to dickite, single-crystal Raman spectra of gibbsite show large perturbations in the v(OH) region and suggest that the interlayer OH groups play a critical role in the phase transformation.journal article10.1029/2002GL0154022-s2.0-0037104932