[meteorite-list] Wierd Meteorite Wrong Question?

[greg stanley]

Adam:

From your picks I would say one of three possibilities, although remember nothing is for sure from the photos on the web.  I really need to view specimens with a hand lens.

Poor grade jasper – I have found this everywhere.  They can be magnetic if it contains hematite and iron oxides.  Although the contraction cracks are not very common in the jasper I have found.  A hardness test will verify this – Jasper is hardness 7.

I fine grained quartzite with desert varnish – I have found these to.  They look igneous to me.  Some are gray, reddish or brown- the grains can very fine.  I have found some very dark.  They are usually not magnetic.  If you look with a hand lens you can see very small grains with a darker coating on them.  And as always – look for any sign of quartz.

I siliceous mudstone – This stuff I have found and been fooled; have even sent samples to UCLA.  The color looks very much like a weathered chondrite.  They sometimes are weakly magnetic, but tent to be not as dense as a stony meteorite.  When cut, they have swirls inside and look very similar to the Jasper or a reddish basalt, but are softer.  I friend of mine calls them “siliceous ooze.” I believe they are formed in an ancient mud settled in a shallow ocean. 

In the Mojave Desert I have found many rocks with all variations of ‘Desert Varnish,’ some coatings on rocks of from bacteria; they can be very tricky, but I keep every one and take it home as you never know.

In your specimen the contraction cracks and high density are good and the fact there was nothing similar is a good sign.

Looks like you have to cut it to make sure.

Greg Stanley
Bakersfield 

--- On Mon, 4/6/09, Adam Hupe <raremeteorites at yahoo.com> wrote:

From: Adam Hupe <raremeteorites at yahoo.com>
Subject: [meteorite-list] Wierd Meteorite Wrong Question?
To: "Adam" <meteorite-list at meteoritecentral.com>
Date: Monday, April 6, 2009, 10:14 AM


Dear List Members,

We went on a Mojave Desert hunt this weekend where I found this weird stone.  My questions is, does anybody have a clue to what type of rock this may be?

The reason I am asking the list is that several hunters have thousands of hours in the Mojave whereas I only have a couple of hundred and they may have seen something like it before. It is very dense, has surface contraction cracks and is not attracted to a powerful magnet at all.  It does look like a crust but not like anything I have ever seen before.  I have never observed a gray crust on a meteorite is what is convincing me that it is terrestrial. I have never seen surface contraction cracks on a terrestrial rock that did not penetrate the whole stone.  We must have hiked 20 miles and I did not come across anything similar.

We thought it was a meteorite when we first saw it in situ but now are not convinced. I do not want to cut it if it is not a meteorite because it would be one of the best wrongs I have ever seen. On the other hand, if there is any chance whatsoever that it could be the first North American Lunar, I would cut it in a heartbeat. Maybe, I am just dreaming but I am convinced that within the next 10 years, some lucky hunter will find one. 

Images of the stone:

Image 1
http://themeteoritesite.com/Achondrite-1.jpg

Image 2
http://themeteoritesite.com/Achondrite-2.jpg

Any input would be greatly appreciated.

Best Regards,

Adam



______________________________________________
http://www.meteoritecentral.com
Meteorite-list mailing list
Meteorite-list at meteoritecentral.com
http://six.pairlist.net/mailman/listinfo/meteorite-list