Crystals in the matrix of a meteroite?

Images made through a microscope. All subject types.

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Walter Piorkowski
Posts: 693
Joined: Mon Aug 14, 2006 6:42 pm
Location: South Beloit, Ill

Crystals in the matrix of a meteroite?

Post by Walter Piorkowski »

ImageImage

Crystals in the matrix of a meteorite?

Nikon S microscope.
Francon Yamamoto reflected light DIC attachment.
PM 40X Nikon Achromat
Nikon 10X CF Photo eyepiece plus PFM 1/2X relay lense
Canon 10D camera.
Photo Shop7 enhancements

OUTER SPACE ROCK UNDER THE MICROSCOPE

A note to you all on how interesting this hobby can be.

Through a friend of mine who recently passed away I acquired a small piece of the Sikhote-Alin meteorite which fell in Russia on February 12,1947. It is a coarsest octahedrite chemical class group IIB. He acquired it from a seller that had cut, polished and etched it so it displays the Widmanstatten features.

One day I started looking at the etched surface of the meteorite with my 1960’s Nikon S series standard incident light unit (EPI) and found it a rather boring subject, but as I spent more time with it at magnifications above 200X I started seeing pieces of flat rectangular crystals. On a hunch it might help I changed the microscope over to my Francon-Yamamoto DIC illuminator and found it astonishingly effective at revealing the crystals I was seeing. For photography of the highly reflective surface it became essential. Some crystals appeared to be laying exposed on the surface but others were clearly partially covered by the meteoric material. With further observation an additional crystal was found, less frequent in occurrence, that again was rectangular in shape, but not flat, it is cubic. Its surface also reacted differently to the tunable fringes of the F-Y DIC device. They always showed a dark surface in DIC illumination vs. the flat crystals no matter how the DIC device is tuned.

I believe that I am seeing crystals revealed by etching, on the etched surface. One knowledgeable meteorite collector I consulted said he never heard of such a thing. His comments were that I was seeing the residue from man made influences, namely the residue from the cutting, polishing, and etching process. He didn't even want to see the images. I also contacted a university professor knowledgeable about this topic but he never responded. Disappointed, I gave up on the idea of investigating further. However, a week later, I came up with the idea of grinding a piece of metal with an aluminum oxide grinding wheel. I found that the microscopic related particles resembled shrapnel, not crystals.

My uneducated guess is that they ARE minerals that were part of the meteoroids internal matrix now exposed by the cutting and etching process. What do you think?

WaltImage

crocoite
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Joined: Wed Aug 02, 2006 3:38 am

Post by crocoite »

Hi Walt. Pretty well all meteorites, whether nickel-iron ones like yours, or chondrodites (stony meteorites) are crystalline when you get to a sufficient level of magnification. Octahedrides are mainly composed of two minerals, kamacite and taenite. Both of these have cubic crystal structures. You are probably seeing one of these species.

Ken Ramos
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Location: lat=35.4005&lon=-81.9841

Post by Ken Ramos »

Other than your subject being a meteorite, I have no idea of what you two are discussing. :lol: However I do find it to be extremely interesting, keep it up. :D

crocoite
Posts: 297
Joined: Wed Aug 02, 2006 3:38 am

Post by crocoite »

Hi Ken

That goes for fungi for me. Although I too find it fascinating. Great world we live in eh?

Ken Ramos
Posts: 7208
Joined: Thu Jul 27, 2006 2:12 pm
Location: lat=35.4005&lon=-81.9841

Post by Ken Ramos »

:lol: Yeah it is Steve! :D

Walter Piorkowski
Posts: 693
Joined: Mon Aug 14, 2006 6:42 pm
Location: South Beloit, Ill

Post by Walter Piorkowski »

Hi Steve thanks for your reply. I was aware of the two minerals you mentioned but had no references to their shapes. I have always been of the mindset that crystals would only form in a void like the geode. Since the meteorite experiment I have reviewed other rocks (from glacial deposites) and see microscopic crystals were only a crevise is present to shelter them.

Fun stuff.

Walt

Charles Krebs
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Joined: Tue Aug 01, 2006 8:02 pm
Location: Issaquah, WA USA
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Post by Charles Krebs »

I'm glad Steve jumped in. This is his type of subject!

Francon Yamamoto reflected light DIC attachment... :smt017
savart plate DIC... :smt017

Where do you find this stuff! :wink:

crocoite
Posts: 297
Joined: Wed Aug 02, 2006 3:38 am

Post by crocoite »

Hi Walt. Minerals don't need a "space" to grow, they can crystalise from a melt. Just really those elements or molecules that have the most attraction from one another. All depends on the chemical composition, temperature, pressure, etc...

Charles - what can I say but "What?!?" :?

Walter Piorkowski
Posts: 693
Joined: Mon Aug 14, 2006 6:42 pm
Location: South Beloit, Ill

Post by Walter Piorkowski »

Hi Charles. eBay, eBay and More eBay.

I am not an expert on the history of the optical innovations as applied to the microscope but in the late 1950's optical engineers were designing all kind of neat things to enhance the effectiveness of the microscope. All we ever seem to hear about these days is Nomarski DIC. Not to knock Mr. Nomarski, but there were many other opticians working on competing ideas.

The designers at Nikon in the 1960s incorporated interesting designs into their microscope line as accesories. I have restored several of the old Nikon S series miroscope frames and own catalogues of the offerings of those days. I have worked for years to aquire these less known devices that I describe in my posts. After spending 20 years with the same old brightfield images I was introduced to darkfield, then phase contrast and I was hooked.

I have had a lifelong facination with the nature and manipulation of light, so this is my way of enjoying myself.

Walt

Charles Krebs
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Joined: Tue Aug 01, 2006 8:02 pm
Location: Issaquah, WA USA
Contact:

Post by Charles Krebs »

Steve...
Charles - what can I say but "What?!?"
Well I sort of see you as the "resident" mineral and crystal guy! When Walter posted this with questions about crystals in a meteorite, I sure didn't have a clue, but I suspected you might. :wink:

crocoite
Posts: 297
Joined: Wed Aug 02, 2006 3:38 am

Post by crocoite »

Hi Charles. No problem with that. The "What?" was for:
Francon Yamamoto reflected light DIC attachment...
savart plate DIC...

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