10 replies to this topic

[t-ara-fan]

I got a rock from a collector who is selling off his collection. Lunar Meteorite NWA 11273.

 

Of course we know the world is full of meteorwrongs, so I took a closer look at it.  The spheres are apparently glass that is common in lunar dust. 

 

 

[t-ara-fan]

One more.

 

[t-ara-fan]

Some color photos of the 0.20g sample.

 

 

[Barlowbill]

I wonder why the spheres have holes?

[t-ara-fan]

I wonder why the spheres have holes?

That is indeed curious.  Interesting stuff for a Cloudy Night.

 

The beads could be 3.4-3.7 billion years old Link

The holes could be gas blowholes - Link

[supex]

Most of what I see is caliche (brown color) so it's hard to say if it is a meteorite unless collector is reputable and you know for sure it is a lunar piece.

[t-ara-fan]

Most of what I see is caliche (brown color)

No. [Insert Grumpycat meme]. Looking at the color is not super scientific.

BTW caliche is calcium carbonate. Carbonates form in environments with water.

Since I posted this, I ran X-ray diffraction on the sample. This sample is anorthite and pigeonite. It contains no water or hydroxide bearing minerals. Almost like it formed on a waterless celestial body

Edited by t-ara-fan, 29 April 2022 - 12:25 AM.

[lee14]

No, it isn't caliche, and those areas don't really have a similar appearance to terrestrial caliche.

 

Classification by appearance is useful, but not definitive. However, the OP's pics do share a good resemblance to other confirmed samples of NWA 11273.

 

The presence of anorthite pretty much confirms lunar origin. Well done on your analysis.

 

Lee

[supex]

I don't want to argue but I've never seen rusty color material on lunar meteorites crust that's part of meteorite unless it's earths material build up, baked on over years.

[lee14]

Most importantly, this color is commonly seen on other examples of NWA 11273. Whether or not is is a true caliche does nothing to rule out classification as a lunar. It does indicate significant time exposed to a terrestrial environment in order to form. Color alone is a poor indicator of origin, it could be related to the interaction between the stone's particular chemistry and composition of the local environment, or even an inadequately calibrated color balance in the image.

 

It's the chemical analysis that confirms this specimen as a lunar, nothing else really matters.

 

Lee

[Ron359]

No, it isn't caliche, and those areas don't really have a similar appearance to terrestrial caliche.

 

Classification by appearance is useful, but not definitive. However, the OP's pics do share a good resemblance to other confirmed samples of NWA 11273.

 

The presence of anorthite pretty much confirms lunar origin. Well done on your analysis.

 

Lee

The "chemical analyses" says nothing about lunar origin.  Anorthite and Pigeonite are common Earth minerals.   Anorthosite rich lunar rocks are all breccias that formed from impacts.  And from the pic, this doesn't look like a breccia.  And the 'holes' or vesicles also indicate its not a breccia since they would only form from gas releasing from a melt or perhaps more likely, weathering on Earth removing some interstitial mineral crystals.   Look at all the photos of Lunar Meteorite NWA 11273 and this rock doesn't look like any i find.  The pics also do not show any fusion crust  even though it appears to be an unbroken, unweathered piece.   https://commons.wiki...gite-358246.jpg

Edited by Ron359, 26 May 2022 - 10:20 PM.