A reinvestigation of holotype wadalite from Tadano, Fukushima Prefecture, Japan

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Marco E. Ciriotti
Messaggi: 24818
Iscritto il: ven 25 giu, 2004 11:31
Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
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A reinvestigation of holotype wadalite from Tadano, Fukushima Prefecture, Japan

Messaggio da Marco E. Ciriotti » ven 18 mag, 2018 18:11

Prossima pubblicazione.

Referenza:
▪ Banno, Y., Bunno, M., Tsukimura, K. (2018): A reinvestigation of holotype wadalite from Tadano, Fukushima Prefecture, Japan. Mineralogical Magazine, 82, (in press).
Marco E. Ciriotti

«Things are interesting only in so far as they relate themselves to other things»

Avatar utente
Marco E. Ciriotti
Messaggi: 24818
Iscritto il: ven 25 giu, 2004 11:31
Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
Contatta:

Re: A reinvestigation of holotype wadalite from Tadano, Fukushima Prefecture, Japan

Messaggio da Marco E. Ciriotti » ven 09 nov, 2018 21:04

Pubblicazione effettuata.

Referenza:
▪ Banno, Y., Bunno, M., Tsukimura, K. (2018): A reinvestigation of holotype wadalite from Tadano, Fukushima Prefecture, Japan. Mineralogical Magazine, 82, 1023-1031.

Abstract:
A reinvestigation of the type specimen of wadalite, ideally Ca12Al10Si4O32Cl6, from Tadano, Fukushima Prefecture, Japan, reveals that it has well-defined chemical sector zoning. The mineral occurs in skarn xenoliths in two-pyroxene andesite and forms tris-tetrahedral crystals up to 1 mm in size. The mineral is cubic, I-43d, with a = 12.009(2) Å, V = 1731.8(8) Å3 and Z = 2. The zoning is divided into two sectors, {21¯1} and {211}, on the basis of back-scattered-electron images. The {21¯1} sector is more enriched in Fe3+, Si, Mg and Cl, and depleted in Al than the {211} sector. The empirical formulae yielded by the averaged compositions for the {21¯1} and {211} sectors are: Ca12.01(Al7.88Fe3+0-99Si4.51Mg0.56Ti0.05)Σ13.99O32.22Cl5.55 and Ca12.05(Al8.42Fe3+0.85Si4.20Mg0.44Ti0.04)Σ13.95O32.19Cl5.38, respectively. Compositional variations in the wadalite grains suggest that the Si contents are controlled mainly by the substitution T(Al,Fe3+) + W□ ↔ TSi + W(Cl,F). The presence of sector zoning suggests that the wadalite grew during rapid non-equilibrium crystallization.
Marco E. Ciriotti

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