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Hi all: With a reflectivity that is more "opaque-like", it is more likely an oxide. Fe-hydroxides have a more subdued reflectance than ilmenite. Exsolved rutile tends to have a more needle-like morphology. I tend to agree with Eric that it is more likely thin ilmenite. Darrell Henry Darrell Henry Campanile Charities Professor of Geology and Geophysics Department of Geology and Geophysics Louisiana State University Baton Rouge, LA 70803 Phone: 225-578-2693 website: www.geol.lsu.edu/henry -----Original Message----- From: Metamorphic Studies Group [mailto:[log in to unmask]] On Behalf Of Pavel Pitra Sent: Wednesday, December 30, 2009 12:11 PM To: [log in to unmask] Subject: Re: mineral to identify Dear Eric, Andreas, Christian, Martijn and all, thanks for your contributions. Yes the lamellae are very thin. In reflected light they are not visible with the exception of the very edge (where the mineral comes to the surface) that is not more than a couple of microns (or even 1µm ?) wide and has a "opaque-like" reflectance. The pleochroisms looks real since the enclosing white micas are not. I have no experience with stilpnomelane... It definitely does not *look* like biotite (but could be biotite exsolution from celadonitic muscovite?). Could it be very thin rutile exsolutions? (from a Ti-rich phengite?; but it seems to have a much lower relief than normal rutile). Please pardon my ignorance, but what are "inclusions of chiller" in pyroxenes? I normally would not bother with Fe hydroxydes, but these look just so conspicuous... and nice. Thanks a lot again! Pavel -- >Pavel, > I would say Fe oxides, Fe hydroxides, Fe >oxyhydroxides are likely. You may have more >than one phase. >cheers, >eric >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......