The crystal structures of 1M-kinoshitalite, a new barium brittle mica and 1M-manganese trioctahedral micas.

Noncentric Layer Silicates: An Optical Second Harmonic Generation, Chemical, and X-Ray Study

“…(Space group symmetry Cm was not checked, because tetrahedral cation ordering is less likely.) For both crystals, the ideal space group, C2/m, accounted for the data better than the noncentric space group, in accord with Kato et al (1979). These results indicate that manganese in the mica structure does not, by itself, promote octahedral cation ordering and that different manganoan micas may have different ordering patterns.…”

Hyperfine electric field gradients and local distortion environments of octahedrally coordinated Fe2+

“…A range of 57° to 61° covers the fl attening angles found in micas. The samples with lowest fl attening angles are several Mn-bearing biotites (Knurr and Bailey 1986;Kato et al 1979) and a norrishite (Tyrna and Guggenheim 1991), and those with highest fl attening angles are samples with germanium in their tetrahedral sheets (Toraya et al 1978;Toraya and Maramo 1981), and an iron-rich biotite (Tepikin et al 1969), although this latter sample appears highly fl attened (59.6°) compared with most biotites (which generally fall between 58° and 59.5°). The (11) -* The values for fl attening angle ( ), counter-rotation angle ( ), and total octahedral sheet-average bond length (d sheet ) are from 170 samples from the database described in Mercier (2003); Fe 2+ -specifi c bond length (d Fe 2+) minimum, maximum, and average are for biotites and olivines in Mercier (2003; see Table 6.6 and Figure 6.74).…”

Oxykinoshitalite, a New Species of Mica From Fernando De Noronha Island, Pernambuco, Brazil: Occurrence and Crystal Structure

“…Guggenheim & Kato (1984) refi ned the crystal structure of kinoshitalite in the subgroups C2, Cm and C1 and confi rmed the space group C2/m proposed by Kato et al (1979). Usually, kinoshitalite has high contents of BaO and MnO and relatively low contents of FeO, Fe 2 O 3 and TiO 2 (Kato et al 1979, Dasgupta et al 1989, Gnos & Armbruster 2000. Only one occurrence of Mn-poor kinoshitalite has been reported (Solie & Su 1987 (Ankinovich et al 1973), anandite, Ba Fe 2+ 3 Fe 3+ Si 3 O 10 S (OH) (Pattiaratchi et al 1967), kinoshitalite, Ba Mg 3 Al 2 Si 2 O 10 (OH) 2 (Yoshii et al 1973a), ferrokinoshitalite, Ba Fe 3 Al 2 Si 2 O 10 (OH) 2 (Guggenheim & Frimmel 1999), and ganterite, [Ba 0.5 (Na,K) 0.5 ] Al 2 (Si 2.5 Al 1.5 O 10 ) (OH) 2 (Graeser et al 2003).…”

“…In addition, McCauley & Newnham (1973) refi ned the structure of synthetic lithian fluorine-dominant analogue of kinoshitalite: Ba 0.97 (Mg 2.23 Li 0.77 )(Si 2.84 Al 1.16 ) O 9.9 F 2.08 , R 1 7.1%, a 5.2858(2), b 9.1575(6), c 10.0375(5) Å, ␤ 100.124(4)°, V 478.3 Å 3 , C2/m. Guggenheim & Kato (1984) refi ned the crystal structure of kinoshitalite in the subgroups C2, Cm and C1 and confi rmed the space group C2/m proposed by Kato et al (1979). Usually, kinoshitalite has high contents of BaO and MnO and relatively low contents of FeO, Fe 2 O 3 and TiO 2 (Kato et al 1979, Dasgupta et al 1989, Gnos & Armbruster 2000.…”

“…Kinoshitalite, ideally Ba Mg 3 Al 2 Si 2 O 10 (OH) 2 , was fi rst described from the Noda-Tamagawa mine, Iwate Prefecture, Japan, in association with hausmannite, tephroite, celsian, quartz, spessartine, rhodonite, chalcopyrite and pyrrhotite (Yoshii et al 1973a (Kato et al 1979), and (Ba 0.54 K 0.41 grunerite, manganoan fayalite and Mn-rich pyroxferroite (Guggenheim & Frimmel 1999 2, c 10.054(2) Å, ␤ 100.53(2)°, was refi ned to a R 1 of 3.2% (Guggenheim & Frimmel 1999).…”