[meteorite-list] Crystals in Lunar Meteorites...?

Thu Dec 30 11:55:14 EST 2010

Thanks Randy:

That answers my question.

Perhaps 2011 will be the year when the first lunar is found in North America.

Good luck to all out there.

Greg S.

----------------------------------------
> Date: Thu, 30 Dec 2010 09:10:32 -0600
> To: meteorite-list at meteoritecentral.com
> From: korotev at wustl.edu
> Subject: Re: [meteorite-list] Crystals in Lunar Meteorites...?
>
> Greg;
>
> Most lunar rocks are impact breccias - rocks made up of bits and
> pieces of older rocks. The pieces are called clasts and they may be
> suspended in a matrix of crystallized impact melt, glass, or
> shocked-compressed smaller clasts. Big clasts are fragments of
> rocks. The smaller clasts are typically single mineral grains. It's
> not uncommon to see clasts of "breccias in breccias in
> breccias." Often, the clasts are cracked and bent as a result of
> shock (visible in thin section). These effects also destroy the
> transparency. It would be rare to see an attractive mineral clast
> with a hand lens on the broken surface of a lunar breccia. Keep in
> mind that the ancient lunar highlands is ~80% plagioclase and the
> rest is mainly pyroxene and olivine. Plag doesn't take well to being
> beat up. You're most likely to see an olivine crystal, but it won't
> be very big.
>
> There are two coarse-grained basalts among the lunar meteorites,
> almost certainly source-crater paired.
>
> http://meteorites.wustl.edu/lunar/stones/mil05035.htm
> http://meteorites.wustl.edu/lunar/stones/asuka881757.htm
>
> They show little evidence of having been affected by impacts (other
> than the obvious - they were found on Earth!). As a consequence,
> they have big crystals, by lunar standards.
>
> Small olivine grains are obvious on NWA032/479
>
> http://meteorites.wustl.edu/lunar/stones/nwa0032.htm
>
> Oh, and a petrographically inclined colleague reminded me yesterday
> that it's "crossed nicols," not "nichols," and that the metal in
> lunar breccias is, in fact, crystalline, though a bit opaque.
>
> Randy Korotev
>
>
> At 06:19 PM 2010-12-29 Wednesday, you wrote:
>
> >Thank you Larry - Sometimes you just can't get your thoughts to the
> >fingertips.
> >
> >Greg S.
> >
> >----------------------------------------
> > > To: stanleygregr at hotmail.com; meteorite-list at meteoritecentral.com
> > > Subject: Re: [meteorite-list] Crystals in Lunar Meteorites...?
> > > Date: Wed, 29 Dec 2010 18:51:46 -0500
> > > From: thetoprok at aol.com
> > >
> > >
> > > Hi Greg, Randy, List,
> > >
> > > I have been wondering the same thing since I've recently cut a few of
> > > my lunar suspects recently. To put Greg's question a little different,
> > > do lunar meteorites ever have crystaline shapes? Can you see with the
> > > naked eye or a loupe actual crystal structures like 6 sided or 8 sided
> > > crystals?
> > >
> > > Sincerely,
> > > Larry Atkins
> > > IMCA # 1941
> > > Ebay username alienrockfarm
> > > www.poisonivycontrolofmichigan.com
> > >
> > >
> > > -----Original Message-----
> > > From: Thunder Stone
> > > To: korotev at wustl.edu; meteorite-list at meteoritecentral.com
> > > Sent: Wed, Dec 29, 2010 11:55 am
> > > Subject: Re: [meteorite-list] Crystals in Lunar Meteorites...?
> > >
> > >
> > > Thanks Randy:It does to some degree and thanks for the links.I keep
> > > reading that lunar rocks contain "clasts," which I interpret as a
> > > grouping of crystals mashed together from a previous rock, and not
> > > individual crystals. I also read "grains" too.Let me put it another
> > > way: Do lunar rocks ever contain large crystals of feldspar or pyroxene
> > > like you may see in granite or a pegmetite? I unfortunately only have
> > > one very small lunar and have only seen others briefly.I'm convinced if
> > > a lunar has lost its fusion crust - it would be very difficult to
> > > identify when found.Greg S.---------------------------------------->
> > > Date: Wed, 29 Dec 2010 13:05:38 -0600> To:
> > > meteorite-list at meteoritecentral.com> From: korotev at wustl.edu> Subject:
> > > Re: [meteorite-list] Crystals in Lunar Meteorites...?>> Greg:>> All
> > > lunar meteorites contain mineral crystals. The basalts (both> breccias
> > > and unbrecciated) are composed mainly of crystals of> pyroxene and
> > > plagioclase feldspar. Some contain olivine, and all> contain minor
> > > ilmenite and related iron-titanium minerals. The> feldspathic breccias
> > > are largely crystalline. The only> noncrystalline material is glass and
> > > a little metal. "Crushed rock"> is crushed crystalline material. In
> > > some lunar meteorites the> plagioclase has been shock converted to
> > > maskelynite which,> technically, isn't a crystal but more like glass.>>
> > > Put another way, in photomicrographs of lunar meteorites (or any> rock)
> > > under "cross-polarized light" (NOT "plane polarized light") or>
> > > "crossed nichols," any and all non-black material is crystalline.>>
> > > There are some here:>>
> > > http://curator.jsc.nasa.gov/antmet/PDFFiles/B07_LAP02205v3.pdf < basalt
> > > >> http://curator.jsc.nasa.gov/antmet/PDFFiles/F23_GRA06157v3.pdf <>
> > > feldspathic breccia >>
> > > http://curator.jsc.nasa.gov/antmet/PDFFiles/F24_LAR06638v3.pdf <>
> > > feldspathic breccia >>
> > > http://curator.jsc.nasa.gov/antmet/PDFFiles/M07_MET01210v3.pdf <>
> > > basaltic breccia >>> Does this answer your question?>> Randy
> > > Korotev>>>>>>> At 11:59 AM 2010-12-29 Wednesday, you wrote:>> >List:>
> > > >> >I hope everyone had a prosperous and joyful Holiday Season.> >> >I
> > > was wondering something:> >> >Do lunar meteorites ever contain
> > > crystals? Or are the just crushed> >rock and lunar soil compacted
> > > together? From what I've been able to> >find is that any basalt type
> > > rock containing white feldspar that are> >crystals or if there is
> > > opaque crystals (ilmenite or> >magnetite...etc.), then it cannot be
> > > lunar, is this true? Are there> >some cases where you could find
> > > crystals within a lunar rock?> >> >Much Thanks and everyone have a
> > > happy New Year.> >> >Greg S.> >>
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