... of rhythmic interlaying of braunite-bearing metasediments (5–15 cm thick) and hematite-rich cherts. Demagistrisite occurs in association with cerchiaraite-(Mn), namansilite, noelbensonite, orientite, richterite, ruizite, and saponite in matrix consisting of braunite, calcite, cryptomelane, orthoclase...

...Marcello Mellini; Stefano Merlino; Marco Pasero Abstract Orientite is orthorhombic, a = 9.044(10), b = 6.091(7), c = 19.031(20) Å, with ideal crystal chemical formula C a 8 M n 10 3 + [ ( S i O 4 ) 3 ( S i 3 O 10 ) 3 ( O H ) 10 ] . 4 H 2 O in the unit cell. A structural model for orientite...

... + ( OH ) 3 [ SiO 4 Si 2 O 7 ] , monoclinic, a = 10.235, b = 6.086, c = 8.970Å, β = 110.75°, space group P 2 1 / m , Z = 2, R = 0.184 for 2437 independent F o and orientite, Ca 2 Mn 2 + Mn 2 3 + ( OH ) 4 [ Si 3 O 10 ] , orthorhombic, a = 9.074, b = 19.130, c = 6.121Å, space group Bbmm , Z = 4, R = 0.156...

...Paul B. Moore Abstract Orientite, © 1965 Mineralogical Association of Canada 1965 ...

...Charles B. Sclar Abstract The optic orientation, optic angle, optic sign, and pleochroic formula of orientite [Ca 4 Mn 4 +3 (SiO 4 ) 5 :4H 2 O] recorded in the literature are incorrect, and a revision of the optical crystallography of orientite is presented. Orientite is orthorhombic, 2 m 2 m 2 m...

... using the ψ scan method ( North et al. , 1968 ). The crystal structure was refined in the space group Cmcm (no forbidden reflections were detected) using as starting values the positional parameters of the orientite structure refined by Moore et al. (1985) , as suggested by the similar...

...-bonding systems. The studied sample was collected from veinlets including macfallite, calcite, orientite, and braunite that occur in basalt located near Manganese Lake, Copper Harbor, in Keweenaw County, Michigan ( Moore et al. 1979 ). Macfallite occurs as needle- and prism-like crystals...

...) and the Miyajima et al. contribution on orientite and macfallite (both complex hydrous manganese silicates), which is complete with chemical analyses, cell parameters and even a listing of the X-ray powder diffraction data! The editor, Richard Hagni, is to be congratulated in producing edited text which...

... & Lindley, 1973 ), orientite, Ca 2 Mn 2+ Mn 3+ 2 Si 3 O 10 (OH) 4 ( Moore et al ., 1985 ; Mellini et al ., 1986 ) and K 3 REE[Si 3 O 8 (OH) 2 ] (REE = Y, Ho, Yb; Maksimov et al. , 1968 ; Ponomarev et al. , 1988 ; Filipenko et al. , 1999 , respectively). The present paper reports the high...

... microfractures and veins (from 0.1 to some millimeters in width) in Jurassic cherts of the “Diaspra di Monte Alpe” Formation. Associated minerals are: quartz, pectolite, orientite and calcite. Other new minerals found at the locality are mozartite, CaMn(OH)SiO 4 , and caoxite, CaC 2 O 4 ·3H 2 O. General...

..., namansilite, orientite–macfallite and cerchiaraite ( Lucchetti et al. , 1988 ; Basso et al. , 1989a , 1989b , 2000 ; Kampf et al. , 2013 ), at variance with the relatively reducing johannsenite-, rhodonite-bearing assemblages of Val Graveglia ( Cabella et al. , 1991 ). The recent findings at Cerchiara...

... of orientite . American Mineralogist , 71 , 176 – 187 . Mugnaioli , E. , Mellini , M. , nieto , F. , and Capitani , G.C. ( 2007 ) Precision and accuracy in the measurement of lattice parameters by electron diffraction . First Meeting of the Italian and Spanish Crystallographic...

.... Neues Jahrb. Mineral. Mon., 373–384. The mineral occurs as individual grains and radial aggregates with quartz, pectolite, orientite, and calcite in fractures that are up to a few millimeters in width. Individual grains are prismatic to acicular, up to 0.1 mm wide and 2 mm long, elongate [001...

... to indicate the major cation at the X-site ( Passaglia and Gottardi 1973 ). The structures and crystal chemistries of pumpellyite-type minerals are closely related to those of several silicate minerals containing disilicate (e.g., sursassite, macfallite) or trisilicate groups (e.g., ardennite, orientite...

... D. and Balestra C. ( 2021b ) Demagistrisite, the missing link in a polysomatic series from lawsonite to orientite . The Canadian Mineralogist , 59 , 91 – 105 . Cámara...

... , P.B. , Shen , J. , Araki , T. ( 1985 ): Crystal chemistry of the ∞ 2 [M 2 3+ ϕ 2 (TO 4 ) 2 ] (sheet: structural principles and crystal structures of ruizite, macfallite and orientite . Am. Mineral ., 70 , 171 – 181 . Nagashima , M. & Akasaka , M. ( 2007...

..., macfallite and orientite. American Mineralogist , 70 , 171 –181. Nagashima, M. and Akasaka, M. ( 2007 ) The distribution of chromium in chromian pumpellyite from Sarani Urals, Russia: A TOF neutron and X-ray Rietveld study. Canadian Mineralogist , 45 , 837 –846. Nagashima, M., Rahmoun, N.-S...