...Maryellen Cameron; G. V. Gibbs Abstract The crystal structure of synthetic fluor-tremolite [ a = 9.787(3) Å, b = 18.004(2)Å, c = 5.263(2)Å, β= 104.44(2)Å, C 2/ m ] has been refined and compared with that of hydroxyl tremolite. Exam ination of the structures reveals that substitution of F for OH...

...J. E. Comeforo; J. A. KOHN Abstract A study of synthetic fluor-tremolite by x -ray and optical methods was considered basic to research on fluor-amphiboles as potential substitutes for asbestiform minerals. A review and critique of previous syntheses is given, together with earlier optical and x...

... compositions. Configurational entropy of mixing models requires W Ri and W Tr to be reduced if the whole solid solution is stable at the synthesis temperature of 1123 K, but not if richterite-rich compositions are metastable. The similarity between Δ H mix of tremolite-richterite and fluor-tremolite-fluor...

...Jung Ho Ahn; Moonsup Cho; David M. Jenkins; Peter R. Buseck Abstract Synthetic hydroxyl tremolite, fluor-tremolite, and magnesio-hornblende together with two natural tremolite samples were investigated using high-resolution transmission electron microscopy (HRTEM). Chain-width defects...

... 3.5 Al 0.5 O 11 ) 2 F 2 , boron edenite, NaCa 2 Mg 5 (Si 3.5 B 0.5 O 11 ) 2 F 2 . Comparisons are made with the values previously reported for fluor-tremolite, Ca 2 Mg 5 (Si 4 O 11 ) 2 F 2 . A detailed indexing of x -ray powder diffraction patterns has been made in the range up to 76° 2θ, and accurate...

...Mark D. Welch; Shuangxi Liu; Jacek Klinowski Abstract We report the compositional systematics of the 29 Si MAS NMR spectra of richterite, (super [A]) (Na,K,Rb) 1 (Na,Ca,Sr) 2 Mg 5 Si 8 O 22 (OH,F) 2 ; pargasite, NaCa 2 Mg 4 AlSi 6 Al 2 O 22 (OH) 2 ; and fluor-edenite, NaCa 2 Mg 5 Si 7 AlO 22 F 2...

...Barbara L. Sherriff; David M. Jenkins; Gerald Kunath-Fandrei; Steffen Goetz; Christian Jaeger Abstract A magic-angle-spinning nuclear magnetic resonance (MAS NMR) spectroscopic study was done on the series of synthetic gallian-fluor amphiboles to identify the extent of Ga and Si ordering...

.... Mercolli, I. ( 1980 ) Fluor-Verteilung in Tremolit und Talk in den metamorphen Dolomiten des Campolungo (Tessin) und ihre phasenpetrologische Bedeutung. Schweizerische Mineralogische und Petrographische Mitteilungen , 60 , 31 –44. Metz, P. ( 1983 ) Experimental investigation of the stability...

... in clinoamphiboles . Science , 153 , 890 – 892 . Cameron , M. and Gibbs , G.V. ( 1973 ) The crystal structure and bonding of fluor-tremolite: A comparison with hydroxyl tremolite . American Mineralogist , 58 , 879 – 888 . Dachs , E. , Baumgartner , I.A. , Bertoldi , C...

... synthetic fluor-richterites. Carnegie Inst Wash Year Book 70:150–153 Cameron M, Gibbs GV (1973) The crystal structure and bonding of fluor-tremolite: a comparison with hydroxyl tremolite. Am Mineral 58:879–888 Cameron M, Sueno S, Papike JJ, Prewitt CT (1983) High temperature crystal chemistry of K...

... –252. Cameron, M. and Gibbs, G.V. ( 1973 ). The crystal structure and bonding of fluor-tremolite: A comparison with hydroxyl tremolite. American Mineralogist , 48 , 879 –888. Carman, J.H. and Gilbert, M.C. ( 1983 ) Experimental studies of glaucophane stability. American Journal of Science...

... in unsorted sandstone-filling paleokarst cavities within the Lower Marble Formation. A green rim on fluor-uvite from the Fowler orebody at Balmat contains 1.37 to 1.59 wt.% Cr 2 O 3 ; fluor-uvite associated with dark green tremolite (0.39 wt.% Cr 2 O 3 ) from the Lower Marble Formation at the Alvin Washburn...

... and no expression in the infrared. Della Ventura et al . (2014) reported a similar absence of a band at 3730–3740 cm –1 in the spectra of fluoro-edenite and fluoro-pargasite. In the infrared spectra of tremolite and fluoro-tremolite, there is a single (OH)-stretching band at ∼3674 cm –1 ( Della Ventura...

... ): Synthesis and infrared spectroscopy of amphiboles along the tremolite–pargasite join . Eur. J. Mineral . 15 , 341 – 347 . Della Ventura , G. , Robert , J.-L. & Hawthorne , F.C. ( 1998 ): Characterization of OH–F short-range order in potassium-fluor-richterite by infrared...

... OH– A Na–OH, OH– A Na–F, and F– A Na–F such that Σ n i = 1. Robert et al . (1999) showed that there is no short-range order of the local arrangements in richterite–fluor-richterite ( i.e ., an A site-filled amphibole) and hence the relative frequencies of these three local arrangements...

... , T i 4 + , B e ; W = ( O H ) , F , C l , O 2 − . Studies of synthetic scandian analogs of fluor-eckermannite, fluor-nybøite, pargasite, and fluor-pargasite show that Sc mainly occupies the M2 sites ( Raudsepp et al. 1987a , 1987b , 1991 ; Oberti...

... . Infrared spectroscopy of amphiboles in the tremolite–fluorotremolite series show a single OH-stretching band at 3674 cm –1 (Jenkins, 1987 ; Gottschalk et al ., 1999 ; Robert et al ., 1999 ), and the position of this band does not change with varying F content (apfu). This ‘one-mode behaviour’ (Chang...

... unusual edenite and actinolite with up to 1.7 and 2.9 wt% Sc 2 O 3 , respectively, from granitic pegmatites and their metagabbro host from the Crystal Mountain fluorite deposit, Ravalli County, Montana, U.S.A. ( Foord et al. 1993 ). On the other hand, scandian analogs of fluor-eckermannite, fluornyböite...

.... , and Turnock , A.C. ( 1994 ) A-site disorder in synthetic fluor-edenite, a crystal structure study . Canadian Mineralogist , 32 , 21 – 30 . Boyd , F.R. ( 1959 ) Hydrothermal investigations of amphiboles . In P.H. Abelson , Ed., Researches in Geochemistry , p. 377 – 396 . Wiley...

... , with a minor band at about 3674 cm −1 . This latter band (tremolite-type band) is assigned to the A-site vacant sites in the amphibole ( Table 1 ). In the spectra of intermediate (OH,F) compositions up to nominal X F ≈ 0.5, the main band broadens and shifts to lower wavenumbers (down to 3705 cm −1 ). For X F...