Newbie Analysis

[MacGyver]

Hello Everyone!

This is my first time posting. I am a total newbie just trying to learn how to identify meteorites. I recently found this suspicious looking rock. Here is what I know....uh...or at least what I think I know :-)

It came from a location not associated with any known find in southwest Arizona.

It weighs 691.728 grams

A magnet is attracted to it although not especially strong.

It displays contraction cracks

it has a very fine matrix

It appears to be something like maybe an LL2

It appears to contain olivine inclusions

It also appears to contain carbonaceous chondrules

It also has white inclusions...maybe silica

I polished a small window and using a loop, I can see several olivine crystals. I think I can see very small traces of iron specks.

Anyone care to give an opinion...It would be greatly appreciated!

Contraction cracks

Another look at cracks

Carbonaceous Chondrules and white inclusions

It attracts a magnet

The window

Thanks,

Rich

[John B.]

Hi Rich

I at first picture thought maybe but the window pix makes me real doubtful. Do you see any free metal in it ?? In the window pix it becomes obvious that it a desert varnish finish and the bottom side is lacking. I would guess granite or some other grainy material.

Maybe some better closeups of the window. I think it's terrestrial but I could be wrong !! Happy Huntin John B.

[billpeters]

Hello Rich,

Your rock has all the characteristics of common Arizona basalt. It is moderately magnetic. AZ Basalt contains magnetic hematite. AZ Basalt frequently has surface cracks very similar to your rock that go into the rock. True contraction cracks do not go deep in to the rock, but are formed only on the surface and are NOT true cracks like your rock. AZ Basalt has a matrix very similar to your photos. Your matrix closeups do NOT match true condrules. Check online. The assessment that these are apparent olivine inclusions is doubtful. The white inclusions are actually quite commonly found mixed with AZ Basalt. The polished window actually gives stronger indication that it is AZ Basalt. The iron specks are questionable. There is no indication of a meteorite crust whatsoever beyond typical desert varnish. It looks precisely like the many 1000s of AZ Basalt rocks that I have encountered while searching in southern Arizona. I actually have a bigger twin of your rock sitting on my front sidewalk. (I kept it because it happened to be quite spherical by geological accident.)

For every 1000 rocks people bring in to be tested as suspected meteorites at the ASU Meteoritical Center only one is actually correct. Meteorites are out there. You are doing the right thing by searching.

Keep looking down,

billpeters

[Regmaglitch]

Hi Rich,

Yes, they're right, it's a fine-grained basalt. Desert varnish, not fusion crust. And real chondrules remain round even when the stone is broken or exposed. Those look like round inclusions where minerals were concentrated. I have at least two samples of that same type of stone in my meteor-wrong pile. Good eye. It means you are looking for the right features. Keep at it, you're going to find a new meteorite!

Good Hunting, Ben

[MacGyver]

Hey Guys,

Thanks for all the great feedback! Funny how my meteor-wrong pile keeps growing :-) I seem to have the most trouble identifying the stoney meteorites. I have viewed thousands of photos of both meteorites and meteor-wrongs and still struggle. What is that saying... "experience is something you don't get until right after you need it" :-) I am still having a great time making all the newbie mistakes though. My father and I used to do a lot of rock hounding when I was a kid so this meteorite hunting feels pretty good. An excuse to get out and enjoy nature! I got bit by this meteorite bug when I stumbled upon an 8 pound iron about 8 months ago. No turning back now :-)

Anyway, back to the suspect rock...I think I'll cut a better window to get a better view. I am pretty sure I am seeing olivine though. The iron specks are still suspect. I have read that some meteorites can contain magnetite which confuses the whole matter for me. Another confusing thing is that I have seen a picture of the Gold Basin Main Mass that to me looks just like my suspect rock with what appears to be fairly deep contraction cracks....or maybe they are impact fractures.....hmmmmmmm.....time to do more reading I guess!

Thanks Again!

Rich