... liquids (i.e., true glasses). Berman also suggests that metamict minerals may be true glasses. While Berman's technique of studying radiation damage (DTA and powder diffraction of material which has been severely damaged by fission fragments) is of obvious value, we do not agree entirely with his...

...A. Muecke; H. Strunz Abstract We discovered two new metamict minerals in the Antsakoa I pegmatite near Berere in Madagascar. They were recrystallized through heating and investigated with the following results: (1) Petscheckite, idealized as U 4+ Fe 2+ (Nb, Ta) 2 O 8 , hexagonal, space group P 3 l...

...J. Graham; M. R. Thornber Abstract Structural relationships and the effects of isomorphous substitution lead to a new interpretation of the phenomenon of metamictization for these minerals. It is proposed that many possible structures exist with about the same stability, each being favored...

...Rodney C. Ewing Abstract Orthorhombic, metamict, AB 2 O 6 -type rare earth Ti-Nb-Ta oxides have VHN 50 values ranging from 633 to 746. VHN 60 increases to approximately 1000 for annealed specimens. Reflectances measured in air vary from 11.9 to 15.6 (470nm),11.7 to 15.6 (546nm), 11.0 to 15.0 (589nm...

...John W. Adams; William N. Sharp Abstract Heating metamict minerals in a nonoxidizing atmosphere for X-ray study is facilitated by a technique using charcoal rather than the customary tube furnace. 1 Publication authorized by the Director, U. S. Geological Survey. Copyright © 1970...

...Shirley J. Gibson; Arthur J. Ehlmann Abstract Chemically analyzed metamict gadolinite was heated in air at varied temperatures and time intervals. At 1080°C gadolinite was well crystallized by 1 hour. At 880°C samples showed a lesser but constant level of crystallinity. At 780°C and 730° the gamma...

...J. Laurence Kulp; Herbert L. Volchok; H. D. Holland Abstract Various specimens of metamict zircon, samarskite, microlite, fergusonite, pyrochlore, and ellsworthite have been subjected to alpha activity measurement, differential thermal analysis and x -ray diffraction analysis. The ratio of the area...

...A. Pabst Abstract The development of investigation of the metamict state is considered. Observations of the changes induced by heating metamict thorite are reported. * Address of the retiring President of the Mineralogical Society of America given at the thirty-second meeting of the Society...

...C. E. B. Conybeare; R. B. Ferguson Abstract Seven metamict pitchblendes, apparently the first to be reported, are described from three localities in the Goldfields area of Saskatchewan. The changes in x -ray powder pattern and color of the powder after ignition are tabulated for these and two other...