Please Help Identify. Can Not Find Anything Like It?

[Heb]

On 4/9/2023 at 3:20 AM, Geologyhound said:

When you say it has some sort of quartz embedded, do you mean it looks like it has sand fused onto it, or do you mean light transmits through it like an agate?

There are several things that come to mind.  Determining which is correct would be difficult without seeing the stone in person.  The surface looks almost like pahoehoe (a kind of lava flow with a billowy or ropey surface).  But, I would not expect that on both sides. The shape of it could be a sort of volcanic spatter bomb.  However, those usually have air pockets.

I concur with Ddancer that the surface morphology does appear roughly akin to some agates.  But, you can also get some interesting surface textures with hematite nodules and ironstone nodules as VicR suggested.  Since you said it is heavy, this makes me think it may be a nodule.  If you scrape one edge of the broken part on a piece of unglazed porcelain and it leaves a red streak, then it is hematite.  If the streak is more yellowy brown, then it could be limonite (a hydrated iron oxide).  If it scratches the porcelain and doesn’t leave color behind, then it is a silicate (e.g. agate).

Something to consider – the French did set off several nuclear devices in the Sahara when they were developing nuclear weapons.  I understand they were lava blobs and fused sand blobs found, but I haven’t seen pictures.  It does not look like any of the nuclear fused glass discovered after the American nuclear tests.  Were you, by any chance, anywhere near where the nuclear testing was conducted?

Whatever it turns out to be, it certainly appears striking and I certainly would’ve picked it up!  Of course, if it’s radioactive I would then also drop it.  😄

This comment!! Almost gave me a heart attack I thought you were going to say a mine. Equally terrifying is that it could be radio active and I’m looking at with suspicion as I type this. I barely  know a thing about rocks so will try to addrsss your questions.

the embedded rock looks like a crystal diamond wedged in I’ll send a close up image. Not sure if light can shine trough seems opaque but white and separate to the rest of the rock

ill try the scratch test on the back of a plate? 
 

thanks for your reply! Yes sadly it is from an area heavily involved in the war with Israel (land mine zones) not sure about the French period. I would say that was more near suiez canal

[Heb]

On 4/8/2023 at 9:24 PM, jasong said:

I don't know but I'll trade ya $100 in gold nuggets for it because it's cool and unique. 😉

I'd be about 90% certain it's a fossil of some kind, maybe some smashed down crinoid stems. I don't know enough about fossils to say though, but I doubt it's specifically geologic in origin alone whatever it is. 

😁😁Would cost a fortune to post! 

[Heb]

On 4/9/2023 at 4:47 AM, jasong said:

Another possibility, if not a fossil, is some sort of preserved texture from an ancient boiling mud pool. The 2 sidedness seems odd for that though too, like lava.  

*that line of thinking led to some odd formations I've never heard of called Gogottes. They don't appear to be in the Sahara though, but perhaps similar processes could form something similar. 

Yes I thought of melting lava which then made me think it could be a meteor. Gogottes look amazing some similarities. Thank you for your input!

[Heb]

Someone on a fossil forum has suggested banded flint?

[Geologyhound]

The older I get the more I’m convinced the less I know. I’m a geologist but I have never heard of gogottes before.  So, nice post there Jasong!

If it is some sort of gogotte, the density is puzzling.  Those should be made of silica sand and calcium carbonate. That should not be that heavy.  Heb, any chance you could do an Archimedes density test on it?  Fill a basin with water clear full, immerse the object, measure the volume of water that overflows, weigh the object and calculate the density.

Can you get a close-up of the matrix of the rock? Does it appear sandy or is it crystalline but too small make out the crystal size?

Yes, a close-up of the crystal would be interesting too.

[Heb]

Some more pics with scratch test. 
 

1st pic. Untouched ceramic

2nd pic when scratched on the broken edge there were no marks coloured scratches.
3rd When scratched on the darkest smooth side there were brown marks.

could have done with a better price of ceramic to be honest , everything I had was glazed 

[Heb]

28 minutes ago, Geologyhound said:

The older I get the more I’m convinced the less I know. I’m a geologist but I have never heard of gogottes before.  So, nice post there Jasong!

If it is some sort of gogotte, the density is puzzling.  Those should be made of silica sand and calcium carbonate. That should not be that heavy.  Heb, any chance you could do an Archimedes density test on it?  Fill a basin with water clear full, immerse the object, measure the volume of water that overflows, weigh the object and calculate the density.

Can you get a close-up of the matrix of the rock? Does it appear sandy or is it crystalline but too small make out the crystal size?

Yes, a close-up of the crystal would be interesting too.

Thank you for your reply, I don’t have any scales here sadly but will get some tomorrow as I’ve been trying to guess the weight for a few days now. It’s so heavy. I will then attempt to do the test as you suggested and let you know. Thanks again. Anything further suggestions on tests I could do to to solve this mystery would be gratefully received! 

[jasong]

I have no clue what that thing is but I'm fascinated by it. I'll pay $100 plus cover all shipping costs to the US if you want to sell it. 😛

I don't even have any more useful input because I'm totally stumped. It looks chert-like to me. From the first pics it appeared to be some kind of shaley/sandstoney material, but I don't think so now. So I don't think it's a petrified mud flow now, and it's not lava. Could be a petrified remain of something formed like gogotte but I doubt that now too. I'm not often completely stumped and out of ideas, but this stumped me... 

It has inclusions of other minerals. Not a conglomerate though, not a breccia from what I can tell. The quartz looking piece, maybe some stray different chert, and it appears to have casts from now missing materials (grains of sand, oxidized and missing grains?) The streak is probably just showing surface oxidation (hematite, rust), which is pretty normal on a lot of rocks in the desert. 

I mean, I guess it could be the seed of some kind of concretion? But that end part you show indicates the pattern is continuous across the end and to the other side, to some degree, while not so on other parts of the rock, it doesn't look like a concretion to me, nor anything that would be formed by weather/wind, but that's just my opinion and nothing more. 

The only thing that makes any sense to me is a fossil. Chert is essentially the remnants of biologic goo from the bottom of an ancient sea, and so it can contain fossils. But that appears to mostly be on the surface, making me question if it's a fossil. But that's still the best guess I have. I'm more like 50/50 now though instead of 90%. 😄 Some strange bacterial/algae colony that grew on the surface of a rock and fossilized? Man, no clue...

[Heb]

4 minutes ago, jasong said:

I have no clue what that thing is but I'm fascinated by it. I'll pay $100 plus cover all shipping costs to the US if you want to sell it. 😛

I don't even have any more useful input because I'm totally stumped. It looks chert-like to me. From the first pics it appeared to be some kind of shaley/sandstoney material, but I don't think so now. So I don't think it's a petrified mud flow now, and it's not lava. Could be a petrified remain of something formed like gogotte but I doubt that now too. I'm not often completely stumped and out of ideas, but this stumped me... 

It has inclusions of other minerals. Not a conglomerate though, not a breccia from what I can tell. The streak is probably just showing surface oxidation (hematite, rust), which is pretty normal on a lot of rocks in the desert. 

I mean, I guess it could be the seed of some kind of concretion? But that end part you show indicates the pattern is continuous across the end and to the other side, to some degree, while not so on other parts of the rock, it doesn't look like a concretion to me, nor anything that would be formed by weather/wind, but that's just my opinion and nothing more. 

The only thing that makes any sense to me is a fossil. Chert is essentially the remnants of biologic goo from the bottom of an ancient sea, and so it can contain fossils. But that appears to mostly be on the surface, making me question if it's a fossil. But that's still the best guess I have. I'm more like 50/50 now though instead of 90%. 😄

Haha thanks Jasong if I do decide to see you will get first offer promise 😁 the fossil people recon it’s not a fossil so I guess have to try and find a way to get it tested. 
 

Thank you so much for your input . I Google everything anyone suggests!

[jasong]

Good luck, just promise to post back here if someone from outside the forum figures out what it is. I gotta know now haha.