Hello Jim, The brown opaque elongated lozenge-shaped crystal(s) which are in cross section in the thin section, very much resembles titanite CaTi[O|SiO4] formerly known as sphene. The cross-section shape is classic for sphene IMO. Sphene is something like 2.5 to 3 times longer on the width axis than on the height axis but this is just memory so please verify that yourself. Mindat.org is a place to do specific mineral searches, BTW.
There is also a complicated Titanium bearing mineral called titanate with an"a": CaAl2Si2O8-Fe2TiO4-FeTi2O5 which I assume as some spinel form based on the description at mindat.org. My guess is that this forms upon interaction with Fe-vapor in subsequent metamorphoses by impact melting of the lunar soil??? I am not saying the crystal you have is titanate but just wanted to impress you with my Googling skills. Just kidding! I mentioned it in case you accidentally get sent to that page owing to similar spelling. Rutile, TiO2 forms blades, needles, and hexagonal prisms--Yet another titanium mineral common in lunar rocks. I caught a slide suggesting a hexagonal "orange structure was possibly a glass sphere" but given the rays within it, that might be rutile. All these minerals have been found in lunar rocks /meteorites AFAIK. For what it is worth, have you considered a cosmic ray track count as well? I don't know the cost but you may have enough left over from TS prep to or the TS itself. Congrats on the research and specimen prep so far: Impressive! Elton --- On Fri, 2/20/09, Suzanne and Jim <[email protected]> wrote: > From: Suzanne and Jim <[email protected]> > Subject: [meteorite-list] need some advice, > I am trying to determine the nature of the > orthorhombic-like opaque red/brown crystals I have seen in a > slice I am considering having analyzed. ______________________________________________ http://www.meteoritecentral.com Meteorite-list mailing list [email protected] http://six.pairlist.net/mailman/listinfo/meteorite-list
