Dear Pavel,
I am not able to recognize the mineral, but you have pretty fluid
inclusions in the accompanying mineral.
Best wishes,
Javier
> Hello,
>
> studying glaucophane + cpx + grt-bearing rocks from Syros (Greece) and
> Ile de Groix (France), I recently came across a tiny but outstanding
> mineral that I am ashamed to admit not to be able to identify. It
> occurs in several samples from both localities, but I never saw it so
> clearly in other rock types (at least I don't remember). I'm attaching
> three photographs of it and would be very grateful for a suggestion.
>
> It is brownish-red to orange, slightly pleochroic with relatively high
> relief and occurs typically as very thin lamellae (inclusions?) in
> white micas, apparently parallel to the cleavage. Locally it also
> ocurs in garnet. It is so thin that the optical properties interfere
> strongly with the mineral hosts. I'm afraid that for the same reason
> microprobe analyses wouldn't be conclusive either. Normally I would
> neglect it as a "iron hydroxyde", but its attractive appearance in
> these sections (and the fact that it seems enjoy such mineral
> assemblages) prevents me from doing so.
>
> Thanks a lot for any suggestions!
>
> Have a nice end of the year, and a good new one!
>
> Cheers,
>
> Pavel
>
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