Pavel Pitra a écrit :
> 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.
In a section really perpendicular to the cleavage of the mica or the
cracks in the garnet , the “mineral” probably must be very thin ? I
agree with Eric.
It looks like the "inclusions of chiller" in pyroxenes.
C......
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