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110830 - Image of the Month for September

PostPosted: Tue Aug 30, 2011 8:09 pm
by Matt Smith
Image
For September we have an image of the Springwater pallasite meteorite. This is a main group pallasite with anomalous properties (PMG-an) first found in 1931 in Canada. Further specimens have been unearthed in recent years. The specimen pictured is part of the Natural History Museum, London collection and is on display at one end of the minerals gallery just outside "The Vault". Click here to view the image in the Gallery.

Re: 110830 - Image of the Month for September

PostPosted: Wed Aug 31, 2011 3:08 pm
by Matt Smith
Interesting point about this stone, I'd be like to hear some opinions. After I posted it yesterday I'd left the meteoritical bulletin webpage for it open in my browser. Today I clicked on a few of the images linked from there (try for yourself here). Every other Springwater specimen I've looked at images of has clearly rounded olivine crystals. Compare any of the images linked from the meteoritical bulletin page to the NHM image I posted above. The specimen on display at the NHM has sharp angular olivines throughout.

I double checked my images and I'm certain my image is of the specimen labeled Springwater. Can anybody find another Springwater example with angular olivines? Any ideas?

Re: 110830 - Image of the Month for September

PostPosted: Wed Aug 31, 2011 5:48 pm
by Barwellian
Hi Matt,

I had exactly the same thought when I saw it, but did not follow it up, dismissed my thoughts as it seemed silly to think they had it labeled wrong. Mike Farmer had several slices of the new finds in Ensisheim and I had noted that they all had rounded olivines similar to Brenham but richer in colour.

http://www.meteoriteguy.com/catalog/springwater.htm

Would be interesting to see what the provenance of the NHM sample is! It reminds me more of a roughly cut piece of Seymchan....seems to have a nasty saw cut mark just like the Russians did when it was first hacked up and distributed.

Can't find any others with angular olivines on google images.

Strabge!

Graham

Re: 110830 - Image of the Month for September

PostPosted: Wed Aug 31, 2011 9:14 pm
by msg-meteorites
Having just searched on Google images for springwater pallasite and also looked at photos on the EOM I can't find any photos of specimens with angular olivine. As Graham says Seymchan tends to have angular olivine, my slice certainly did.

Talking about pallasites, anyone yet bought any conception junction, the new pallasite announced my Dave Gheesling, Robert Ward and Karl Aston? Some nice slices available but at a price!

Re: 110830 - Image of the Month for September

PostPosted: Wed Aug 31, 2011 10:09 pm
by Barwellian
Hi Martin,

Hope you are well.

Was looking at Conception Junction but as I think it is low Ni my thoughts are that it may be quite unstable....but that remains to be seen....that's always the gamble with pallasites. Might gamble on a very small piece and test it out.....the documentation that Dave produces alongside it will be worth getting regardless.

Any progress on the Wold Cottage monument restoration research?

Cheers,

Graham

Re: 110830 - Image of the Month for September

PostPosted: Wed Aug 31, 2011 10:25 pm
by msg-meteorites
Hi Graham,

Yep, all good here. Regards Conception Junction, I noted the low nickel content too but Dave's experimented and over the last year even pieces left out without dessicant have been fine. Given the dry cutting and polishing means hopefully it will be ok. I have been tempted by a smallish slice myself which is on hold for me. The story of the find a la Nininger style and Daves monograph make it interesting for me. Fingers crossed it stays stable! It will certainly be kept with a lot of dessicant!

Hope things are good with you and your new house plans are coming into fruition!

Cheers

Martin