Fehér Béla (szerk.): Az ásványok vonzásában, Tanulmányok a 60 éves Szakáll Sándor tiszteletére (Miskolc, 2014)

Ozdín Daniel - Szakáll Sándor: A Miskolc-lillafüredi axinit-(Fe) kémiai összetétele

Chemical composition of axinite-(Fe) from Miskolc-Lillafüred

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Fig. 5. Euhedral, chemically zonal crystals of axinite-(Fe) in association with calcite (dark grey) and albite (black).

BSE image.

5. ábra. Idiomorf kémiailag zónás axinit-(Fe) kristály kalcittal (sötétszürke) és álhittől (fekete) társulva. Vissza- szórt-elektronkép.

Fig. 6. Chemical composition of axinites from Miskolc-Lillafüred and other occurrences from the Western Carpathians (in apfu). 6. ábra. Miskolc- Lillafüredről és a Nyugati-Kárpátok egyéb előfordulásaiból származó axinitek kémiai összetétele (atom per képletegységben).

stitution is typical for second trend of axinite-(Fe). Axinite-(Fe) consists of two generations, the first one makes up the majority in this studied locality and is mostly Fe-enriched. The second generation has formed by repeated hydrothermal processes and is enriched in Mg. Axinite-(Fe) II forms thin veinlets in the axinite-(Fe) I (Fig. 2). The average empirical crys- tallochemical formula of the axinite-(Fe) from Miskolc-Lillafüred is (Ca3 985Na0 003 K^.oo2Mn0 on)£=4.ooo(Fe2+i.i22]VIgo.535Mn0 319Ca0 014Zn0 006Ni0 002Ti0 002)s=2.ooo(Al3.825 Fe3+0.145’^0.002Cr0.00l)£=3.974[(Bl.929^Í0.07l)E=2.000(SÍ7.968Al0.032)£=8.000O30][(OH)1 839F008g Clo.oo20o.ooik=i.93i (n = 29). Empirical formulas were calculated on the basis of the occupation of individual elements at each position according to work of Andreozzi et al. (2004). A content of oxygen and (OH) in structural position W was calculated on the basis of charge balance.

On some of the crystals we observed that the core of the crystals is enriched in Fe and the rim is enriched in Mg. By comparing the chemical composition of the zonal crystals of axinite-(Fe), we found that the central parts of the crystals (light grey in BSE image)