[meteorite-list] Fw: RFSPOD - February 9, 2010 Buzzard Coulee Blue Inclusion

From: Peter Davidson <P.Davidson_at_meteoritecentral.com>
Date: Thu, 11 Feb 2010 12:25:17 -0000
Message-ID: <D7171847AEFC6A4893D80C75E547E271010EF8B6_at_nmsmail02.nms2k.int>

Hi Guys

Zelimir, your reasoning is very sound. There are many minerals that, though they are not normally blue, often exhibit a tarnish that can appear blue. I doubt if bornite is the mineral in question - though without examining the material in close-up it is impossible to say. Chalcopyrite is a stronger possibility. We, in our collections, have a few very fine samples of what is sometimes called "Peacock Ore". This is chalcopyrite that has been tarnished and can appear in a rainbow of colours - as the name suggests - but it can be bright blue. Bornite can tarnish as well and, indeed, some specimens on the market that are marketed as bornite are acid treated chalcopyrite.

Cheers

Peter Davidson
Curator of Minerals
 
National Museums Collection Centre
National Museums Scotland
242 West Granton Road
Edinburgh
EH5 1JA
Phone: +44 131 247 4283
p.davidson at nms.ac.uk
www.nms.ac.uk
 
 
-----Original Message-----
From: meteorite-list-bounces at meteoritecentral.com [mailto:meteorite-list-bounces at meteoritecentral.com] On Behalf Of Zelimir Gabelica
Sent: 11 February 2010 11:38
To: Jeff Kuyken; Meteorite List
Subject: Re: [meteorite-list] Fw: RFSPOD - February 9, 2010 Buzzard Coulee Blue Inclusion

Hi Jeff, all,

The presence of Bornite inclusions in BC as
suggested by John and you, is indeed interesting.

As a mineral collector familiar with various
shades exhibited by metallic minerals, indeed
Bornite, typically bluish, is the first to come in mind.
But I also have in collection quite a few
Chalcopyrites showing a similar blue or bluish-magenta shade.

Chalcopyrite is currently brass-colored (color
similar to Pyrite, though different and thus
making Pyrite and Chalcopyrite easily discernable
from each-other only by considering their color
or glitter...) and I believe (but did not check
so far) that its blue color might indeed stem
from some "chemical restructuration" (I prefer
not to use the term "oxidation", that might be here too specific).
Indeed, when you break some (brass-colored on
surface) Chalcopyrites, you can sometimes find
such blue areas inside the fresh fracture.

I then followed your idea to Google
"Chalcopyrite" and, indeed, some of them show
blue areas or are even completely blue:

http://images.google.fr/images?hl=fr&um=1&q=chalcopyrite&sa=N&start=21&ndsp=21

Apparently the blue shade could be related to the presence of copper.
Bornite is Cu5FeS4, while Clalcopyrite is CuFeS2.
Note that Pyrite (FeS2) does not contain copper and is never blue.

I remember a few other "metallic" minerals that sometimes show blue shades.
They are (from memory): Meneghinite (Pb13 Cu Sb7
S24), Germanite (Cu26 Fe4 Ge4 S32), Briartite
(Cu2ZnGeS4) or Renierite ((Cu,Zn)11 (Ge,As)2 Fe4 S16)
(formulas just taken from the Fleitscher's
"Glossary of Mineral Species, 2008", that I always have on hand)

I don't claim that the last 4 minerals are
present in meteorites (quite unlikely) but I note
similarities with Chalcopyrite and Bornite, which are the following:

All 6 minerals involve Cu, Fe and S (S as sulfide, thus anion)

This being, Bornite and Chalcopyrite involve the simplest formulas.

Considering the Cu/Fe ratio in these 2 minerals
and the scarcity of Cu in meteorites (with
respect to Fe that is far more abundant),
obviously Bornite (that contains 5 times more Cu
than Fe) is less likely to be present in
meteorites than Chalcopyrite in which the Cu/Fe molar ration is one.

Jeff, note also that in your second link,
Chalcopyrite is more often cited than Bornite as
"terrestrially weathered iron meteorite mineral"....

These are my first speculations and hopefully
they will generate more ideas regarding this
intriguing issue (metallic-like blue spots in
meteorites, that I believe are definitely
different than the blue hibonite-containing
"chondrules" or "CAI" we discussed bout previously).

Best wishes,

Zelimir


At 10:48 11/02/2010, Jeff Kuyken wrote:
>Hi all,
>
>Thanks for everyone's input. Firstly, Robert... one of the initial thoughts
>I had was exactly the same in regards to the silver streaks on Ash Creek.
>Maybe it is a related type of feature.
>
>And Mark, you're not really mistaken. Mine appears on the surface of the
>trailing side of the oriented individual. I say surface and not crust
>because it does look like an interior metallic inclusion which is showing
>through and coloured. Gary's awesome pic of his L3 with the interior
>inclusion is very much like mine but on a smaller scale. It could be quite
>possible that they are one and the same thing so maybe it is a result of
>oxidation and not an ablation thing.
>
>Has there been any documentation of metallic inclusions in Buzzard Coulee?
>(i.e. Fe/Ni, FeS, etc) In other falls like Bensour, this was specifically
>mentioned in the classification data. It would seem there are quite a few
>people who have noticed them in Buzzard stones now too.
>
>John's suggestion of Bornite is very interesting. I had never actually heard
>of it before, but it does look VERY much like that. A brilliant iridescent
>blue.
>
>http://images.google.com/images?hl=en&safe=off&q=Bornite
>
>When I googled Bornite and meteorites, the Meteorites Knowledge Base came up
>as a hit. It lists it as "terrestrially weathered iron meteorite mineral".
>
>http://www.site.uottawa.ca:4321/meteorites/index.html#bornite
>
>So if this is an oxidation thing as a few have suggested now, I'm wondering
>if it happened on the ground or during ablation in the disturbed wake at the
>back of the stone and in the bottom of an indent?
>
>Cheers,
>
>Jeff
>
>>
>>----- Original Message ----- From: "Mark Bowling" <minador at yahoo.com>
>>To: <meteorite-list at meteoritecentral.com>
>>Sent: Thursday, February 11, 2010 4:09 PM
>>Subject: Re: [meteorite-list] Fw: RFSPOD -
>>February 9,2010 Buzzard Coulee Blue Inclusion
>>
>>
>>I must have been mistaken, I thought somebody
>>was talking about coloration on crust and not interior features....
>>
>>Mark B.
>>Vail, AZ
>>
>>
>>
>>----- Original Message ----
>>From: Gary Fujihara <fujmon at mac.com>
>>To: Jeff Kuyken <info at meteorites.com.au>
>>Cc: Bernd Pauli <bernd.pauli at paulinet.de>;
>>meteorite-list at meteoritecentral.com
>>Sent: Wed, February 10, 2010 7:21:54 PM
>>Subject: Re: [meteorite-list] Fw: RFSPOD -
>>February 9, 2010 Buzzard Coulee Blue Inclusion
>>
>>Aloha Jeff, Bernd, et al,
>>
>>I am at a conference now and have limited
>>access to email, but was informed of this
>>interesting anomalous inclusion in Jeff's
>>Buzzard Coulee meteorite. My friend and partner
>>of the NWA (~L3, W0/1) has identified a similar
>>feature in one of my slices. Please have a look
>>at my 20.11g full slice to see this blue
>>feature in the middle of a troilite inclusion:
>>
>>http://bigkahuna-meteorites.com/Images/614g/_20.11b.jpg
>>
>>Because this is from the interior of the
>>meteorite, it should dispel any theory of
>>fusion reaction during ablative flight.
>>
>>gary
>>
>>On Feb 9, 2010, at 11:38 PM, Jeff Kuyken wrote:
>>
>>>Hi Bernd & all,
>>>
>>>Maybe it's possible but it's about 150X bigger
>>>than my Isheyevo Hibonite-bearing CAI or
>>>chondrule. Probably too big? Actually, I wish
>>>you could see this feature in person Bernd.
>>>The best way I can describe it is to say that
>>>is looks just like the iridescent blue colour of a Peacocks feather.
>>>
>>>I was sent a pic off list by another collector
>>>who has a similar smaller feature on a very
>>>fresh NWA (~L3, W0/1). There is a brassy
>>>yellow one (troilite?) with a smaller blue one
>>>like mine next to it. Both look like melted
>>>metal on the surface. I know Mark had one
>>>other much larger Buzzard with a similar thing
>>>too. Has anyone else seen this or know what could cause it?
>>>
>>>Cheers,
>>>
>>>Jeff
>>>
>>>----- Original Message ----- From: "Larry &
>>>Twink Monrad" <larrytwinkmonrad at comcast.net>
>>>To: <meteorite-list at meteoritecentral.com>
>>>Sent: Wednesday, February 10, 2010 11:18 AM
>>>Subject: [meteorite-list] Fw: RFSPOD -
>>>February 9,2010 Buzzard Coulee Blue Inclusion
>>>
>>>
>>>>
>>>>Subject: RFSPOD - February 9, 2010 Buzzard Coulee Blue Inclusion
>>>>
>>>>>Hello Jeff K., Michael J., Zelimir and List,
>>>>>
>>>>>I am wondering if this blue metallic inclusion in Jeff's Buzzard Coulee
>>>>>might be one of these hibonites that Zelimir showed us and that Jeff
>>>>>Grosman identified for us.
>>>>>
>>>>>This made me think of the MUCH-1 and "Blue Angel" inclusions in Murchison
>>>>>(both of them hibonite-bearing aggregates).
>>>>>
>>>>>http://www.rocksfromspace.org/February_9_2010.html
>>>>>
>>>>>Jeff, sincere congrats on such a fine Buzzard Coulee!
>>>>>
>>>>>
>>>>>Best wishes,
>>>>>
>>>>>Bernd
>>>>______________________________________________
>>>>Visit the Archives at
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>>>
>>>______________________________________________
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>>
>>Gary Fujihara
>>Big Kahuna Meteorites (IMCA#1693)
>>105 Puhili Place, Hilo, Hawai'i 96720
>>http://bigkahuna-meteorites.com/
>>http://shop.ebay.com/fujmon/m.html
>>(808) 640-9161
>>
>>
>>
>>
>>
>>______________________________________________
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>>
>>______________________________________________
>>Visit the Archives at
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>>
>
>______________________________________________
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Prof. Zelimir Gabelica
Universit? de Haute Alsace
ENSCMu, Lab. GSEC,
3, Rue A. Werner,
F-68093 Mulhouse Cedex, France
Tel: +33 (0)3 89 33 68 94
Fax: +33 (0)3 89 33 68 15

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Received on Thu 11 Feb 2010 07:25:17 AM PST