[meteorite-list] Lawrencite-like oozing from an H6 Impact Melt Breccia

From: Mal Bishop <magbish3_at_meteoritecentral.com>
Date: Thu Apr 22 10:04:51 2004
Message-ID: <5.1.0.14.2.20020522092955.0327d008_at_mail.lig.bellsouth.net>

Thanks to all that have responded so far, Ron H., Mike F., David C., Guy
S., David H.,
Matteo C., Tracey L., and Christian A. -- hope I didn't miss
anyone! Sorry, if I did!

I guess I've just been pretty fortunate with the vast majority of my "H"
stony meteorites as far as Lawrencite goes,
but rust is another story!

I've had some problems with rust like on El Hammami (due to camel sweat as
the story goes, but I'm pretty sure atmospheric conditions of just being on
Earth had very much to
do with that as well). As far as Kunya-Urgench goes, basically all brown
from rust, but holding up well otherwise, no oozing
so far at least, and I've had it for over 3 years (although I understand
that a good portion of the single meteorite sat for some
period of time in water or at least in a marshy like environment until it
could be removed -- am I correct on this?).
I've also had a problem or two with Pallasites like Brahin (rust), but
never any "Lawrencite" (ferrous chloride)
type oozing. But again, as I've said many times already, I'm no expert and
my experience level I still consider
intermediate even after 10 years of enjoying the hobby.

As Ron has mentioned, I do realize H's do have a lot of iron (i.e. free
metal (nickel/iron) not chemically bound in mineral form -- did I put
that fairly close to correct, Ron?) and would have a high tendency to rust,
but like I said, I just haven't read or remember hearing
anyone complain about this condition before with stony's -- just
irons. However, senility does begin early in my family. :-)

Finally, from what I understand, when it comes to Dhofar 010 only several
pieces totaling around 3.5 kg were found in Oman,
and being pretty badly weathered (W3), the epoxy was used to hold the cut
pieces together during finishing as they were rather
cracked and had a strong potential to break during the polishing
process! However, I doubt seriously that the epoxy has anything
to do with this, for one thing, my particular piece has hardly if any at
all, and secondly, the oozing on my piece is no were
around any of the fractured areas!

Believe it, or not, I'm through --

Mal


At 11:31 PM 5/21/2002 -0700, you wrote:
>Hi Mal,
>
>Yes, believe it or not stones can and do have the "Lawrencite" disease. The
>same greenish-ooze! There is considerable iron in stones too, and it does
>happen. I have an El Hammami that is terrible in this regard, and some
>Saharan H chondrites as well. I'd treat it the same way as you have, in
>anhydrous alcohol (not even 99%).
>Blot the ooze at once, don't let it get started, and change the alcohol
>often until it stops. It will give up eventfully.
>
>Ron Hartman
>
>----- Original Message -----
>From: Mal Bishop <magbish3_at_bellsouth.net>
>To: <meteorite-list_at_meteoritecentral.com>
>Sent: Tuesday, May 21, 2002 5:10 PM
>Subject: [meteorite-list] Lawrencite-like oozing from an H6 Impact Melt
>Breccia
>
>
> > Hi List,
> >
> > First of all, "Hi", to everyone on the list new and old, and I don't mean
> > age wise! :-)
> >
> > I'll get to my question in a minute, but I wanted to make an observation
>first.
> >
> > I've been on and off of the list for 3 or 4 years, but lately (last year
>or
> > so) mostly
> > a lurker. Back in the earlier days there were some on this list more
> > interested
> > in stirring up the "mix" so-to-speak than carry on any meaningful
>dialogue,
> > transfer of knowledge, or just plain enrich the passion of others on the
> > list that really
> > wanted to "talk" meteorites! After a few unpleasant run-ins and realizing
> > that it
> > appeared the list was really nothing much more than an on-line market for
> > dealers
> > and collectors wishing to trade/sell meteorites, and most of the remaining
> > threads
> > involved the aforementioned malarkey, I just kind of slipped into the
> > background and hung
> > around waiting for that relatively rare and interesting tidbit of info
> > actually concerning
> > meteorites! There were a handful of regular contributors, and experts
>that
> > came
> > through back then just as they still do today, and I think most of you
>know
> > the individuals
> > I'm referring to!
> >
> > The reason for the above statement is to my great pleasure and enjoyment,
> > this list has changed for the better and is getting better all of the
>time.
> > I think there were many members, in fact I know there were some members
>for
> > they emailed me privately with the same concerns, whom would not join in
> > out of
> > fear of being ridiculed and harassed. Well, it seems as if it is all
>water
> > under the bridge now!
> >
> > Now to my question... I recently purchased a beautifully prepared part
> > slice of Dhofar 010
> > which is an H6 impact melt breccia. It shows a very dark black melt (the
> > matrix material)
> > surrounding the lighter brown unmelted clasts sparkling with tiny bits of
> > metal. I've had it now for almost a month.
> > The past week, week and a half, I noticed that it has dark, brown,
>greenish
> > looking droplets of moisture
> > oozing out on the back unpolished side and a couple of droplets on the
> > front highly polished side. Right away I thought Lawrencite
> > and Nantans not to mention a couple of other irons and Pallasites, but
>this
> > is an ordinary chondrite (H6)
> > and I just haven't heard of this problem with chondrites. If they
> > [chondrites] can have the "disease" as well
> > as irons then I'm just ignorant of it! Even under just a 10x magnifier,
>it
> > looks like the "cancer" of irons as,
> > I think, Richard Norton put it. I have or had many different types of
> > chondrites, and many of course, are or were
> > ordinary ones from LL's to H's an 3's to 6's, but I never saw this before
> > -- I haven't read or heard anyone else speak of this either!
> > When I wipe the moisture off, it will have returned again within the next
> > day or two.
> >
> > Another interesting fact is that the oozing appears to be coming from the
> > melt (matrix) surrounding the
> > clasts (breccia) on the back side and not from any of the clasts
>themselves
> > that I can tell. Of course, I could
> > be very wrong for I'm by no means an expert -- just learning all the time.
> > The polished front side seems to really have only one area and it is a
>tiny
> > clast, but this clast has a couple
> > of small holes or pores -- therefore, I suspect it's just bleed through
> > from the back side where the melt happens
> > to line up from behind that particular clast!
> >
> > Believe it or not, in the past with a couple of Nantans that after cutting
> > started oozing very badly, I'd soak
> > them for days, weeks, and even months in anhydrous isopropanol (isopropyl
> > alcohol). When the solution
> > began looking brown or somewhat less than perfectly clear (to my
>subjective
> > eye) I would exchange it
> > for pure alcohol again. I would do this probably 2,3, or 4 times
>depending
> > on the tenacity of the iron involved --
> > maybe more. This stuff I use is 99.995% water free and it WILL dry out
> > whatever you have in mind -- including your fingers! ;-)
> > But the point is, after whatever period of time it took and the particular
> > Nantan piece involved, I eventually
> > got the blasted thing to stop oozing. One I'm soaking right now has been
> > in solution for nearly one year.
> > I take it out occasionally and just let it sit for several days to see if
> > it begins oozing again, so far, so good!
> > My next step will be to let it sit in the display case for several weeks
> > and keep an eye on it. If all goes well
> > I may or may not clearcoat it.
> >
> > I said all of that just to point out nothing, I guess really, with my
> > question at hand other than if nothing else the alcohol
> > bath should do the same trick if it is Lawrencite or something
> > related. Like I said though, I'm far from any expert with
> > preparing, conditioning, and maintaining irons or any meteorite (or rock)
> > for that matter, but I try a little, learn a little,
> > read a little, and learn a little more!
> >
> > SORRY for the lengthy email, but I'm just curious, concerned, and ready to
> > learn more from this distinguished
> > and informed list of members!
> >
> > Anybody have any answers, similar occurrences, or whatever?
> >
> > Regards,
> > Mal
> >
> >
> >
> > ______________________________________________
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> > Meteorite-list_at_meteoritecentral.com
> > http://www.pairlist.net/mailman/listinfo/meteorite-list
> >
>
>
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Received on Wed 22 May 2002 10:48:28 AM PDT