FMF - Friends of Minerals Forum, discussion and message board

[ALshawani]

Who can help me identify these stones

[Vinoterapia]

it does not look like a volcanic rock, probably chert.

[Josele]

Check hardness trying to scratch a bottle glass. Then clean with your finger and make sure there is a permanent scratch on glass. If so you have some sort of quartz.

And please read instructions and give locality data.

[James Catmur]

These are the tests we ask you to perform

https://www.mineral-forum.com/message-board/viewtopic.php?p=19487#19487

If the hardness is 7 then I think it is chert/flint

[ALshawani]

Thank you for the instruction link to view stone
In terms of hardness, it is greater than 7 because quartz does not scratch this stone. I used to think it was an agate. It looks like agate, a yellowish to brown color with white circles in the middle.

[nano]

rhyolite chalcedony it can be:) volcanic

[Vinoterapia]

I do have some small samples of chert from Burke County, Georgia. They look quite similar to yours. Those are interesting because in the crevices is non uncommon to find cacoxenite and other microminerals. If it is possible check your samples under a microscope.

[nano]

If it chert it can make fire :)

[James Catmur]

Does it scratch quartz? If not then its hardness is 7

[James Tate]

I truly believe your sample is very important. This is the first piece of material that's really caught my attention around here in quite a while.

And, I'll be the only person here that will propose that you've discovered a piece of asteroid impact melt rock. I'll also guess that you found this material sample somewhere within the southeast Libyan Desert area and indeed connected with the infamous Libyan Desert Glass.

Your first statements involved a theory of volcanic origin, likely from noticing other rocks in the area clearly affected by extreme heat circumstances, such as vesicular melt structures and translucent glass-like properties.

I noticed some (Fe) coatings around small circular rings in the upper right area of the sample. This is consistent with (Fe) flecks found within impact-related Libyan Desert Glass.

I'm assuming that many more samples that match this one exist within the area where you found it. As one post suggested, try to locate some samples that might offer some more evidence factors such as "shocked minerals," with planar deformation features under a microscope. Other than confirming high-pressure minerals such as Coesite, this is likely the only way to confirm an asteroid impact-related material vs. a volcanic or terrestrial origin.

I'll include some photos of my own impact-related materials that closely match your sample. My WIS samples also plow through quartz and likely reach a hardness factor of 8-9. Further evidence of extreme high-pressure origin.

The WIS impact-related materials are considered to be Proximal Ejecta Material. If your samples are indeed the same type of impact-related materials I suspect them to be, this could be very important in discovering an elusive (yet discovered) impact crater (target area) location responsible for the origin of the Libyan Desert Glass (Tektites), strewn throughout the western border of Egypt

Please feel free to PM me with any further questions, as I'm sure I would have more for you as well.

Your Friend,

James Tate

[ALshawani]

Thank you I'll try it

[ALshawani]

Thank you, it really stimulated me, and I am also sure that there is a high temperature in the place in terms of the rocks affected by the heat, and for this I had said that it is in the volcanic rocks, but the area in which I found it is the western region close to the Tunisian border and a mountainous area and there are traces of very old excavation in the place maybe since 2000 A year or more ago ...
In terms of the samples that I attached, I think I saw a lot like it in the place....

[James Tate]

Al,

You've got an intriguing mystery on your hands. The fact of your material found near the Tunisian border gave me a better search area for a suspected impact crater location. The infamous Libyan Desert Glass is located over 1600km away, and likely not connected.

However, I would consider that more interesting and creates an opportunity to discover and confirm an unknown asteroid impact site. I've been studying the science of impact crater morphology for quite a while now, and I've got your first candidate to consider and possibly explore.

*Interesting question: How difficult is it to get across the Tunisian Border?

I'm very curious what other types of impact-related materials might exist in the area, and if you can possibly get to the suspected impact crater area (pictured below), we can review what types of material would be considered diagnostic evidence of impact. Such as...Shatter Cones, Impact Breccia, Impact Melt Rocks, and anything exhibiting planar deformation features (PDF's) caused (only) by high-pressure impact circumstances.

Take your time researching some examples of impact-related materials, and I'm more than willing to share any information and photos of my own impact-related material samples as well. (including my secret W.I.S. Impact Crater)

I'll give you a fair warning. Once you get into an impact-related discovery...regular earth-rocks will never be the same.

Your Friend,

James Tate

[ALshawani]

[ALshawani]