Chemistry of Kornerupine and Associated Minerals, a Wet Chemical, Ion Microprobe, and X-Ray Study Emphasizing Li, Be, B and F Contents

Hyalotekite from reedmergnerite-bearing peralkaline pegmatite, Dara-i-Pioz, Tajikistan and from Mn skarn, Långban, Värmland, Sweden: a new look at an old mineral

“…The microprobe analyses gave reasonable totals (average = 99.61 wt.%) and stoichiometries in good agreement with the crystal structure deduced by Moore et al (1982), that is average Si + B + Be + Fe = 11.961, Ca + Mn + Na + Sr = 2.033, Pb + Ba + K = 4.007, and average total cations, 18.001. The Pb/Ba ratio of sample 114716 exceeds that reported by Moore et al (1982) (Grew et al, 1990), and thus the ion microprobe data are not conclusive evidence for a deficiency in F relative to the one F p.f.u, reported by Moore et al (1982). Charge balance calculated from the occupancies reported by Moore et al (1982) requires 0.76 F + 0.24 O on the F site, in good agreement with Lindstrrm's F content (Table 3).…”

“…The following standards and sensitivity ratios were used: spodumene (Li/Si), surinamite (Be/Si), grandidierite (B/Si), and biotite (F/Si and Ba/Si); 3.3 (Rb/Si), 3.7 (Sr/Si), and 5.5 (Cs/Si). Ion microprobe data for kornerupine (sample BM1940,39), which was analysed concurrently with hyalotekite and taramellite, are in fair to good agreement with the wet chemical data of Grew et al (1990, in Grew et al (1990) Tables 3-6 in order to minimize rounding-off error in future calculations.…”

Occurrences of boron-free and boron-poor kornerupine

“…In consequence it is recommended that the term 'boron-free' is specifically not used unless boron has been adequately analysed for and not detected (e.g. Droop, 1989;Grew et al, 1990). When considering the designition of trace elements in a mineral, weights of less than 0.1 wt.% are…”

“…The literature (e.g. Grew et al, 1990) contains an increasing number of ko.rnerupine analyses which include B. When B vs. A1TM is plotted, a clear linear correlation emerges (Fig.…”

Tourmalinites in the metamorphic complex of the Svratka Unit (Bohemian Massif): a study of compositional growth of tourmaline and genetic relations

“…Based on chemical composition and textural relationship with other rock-forming minerals, dravite rich in F and Na, and having a low X-site vacancy (zone II) overgrowing or replacing the schorl core (zone I), probably corresponds to crystallization of tourmaline in the course of prograde metamorphism. Elevated P-T conditions stabilize increased F and Na in tourmaline, and a high X Mg is characteristic of tourmaline crystallized in metapelites under amphibolite-facies conditions (Henry and Guidotti 1985;Grew et al 1990;Dutrow 1996, 1997). Because of the tourmaline's wide stability range (Werding and Schreyer 1984), the primary composition of this mineral in tourmaline-rich rocks of many localities worldwide (e.g.…”