Please Help Identify. Can Not Find Anything Like It?

[Heb]

Hi there thanks for your help. This stone was found in the Sahara desert. I thought it was a fossil but to be honest I have no idea what it is. Any help would be appreciated. 
 

seems carved but maybe could be natural markings,

extremely heavy. Sound 30cm x 20cm,

some sort of quartz stone embedded.

[DDancer]

My thought is that its a wind eroded agate.  Abrasion, in this case by sand, on the harder and softer parts of the agates banding can give a very sculpted appearance.  I've seen simulur in agates from water courses.

[jasong]

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. 

[VicR]

Could be a Iron Oxide Concretion - they can give that layered effect.

[VicR]

Google below for more information on Iron Oxide Concretions.

 

ozgeotours.yolasite.com/resources/concretion.pdf  

[mn90403]

I've seen two faces in it and I'm sure there are more!

[Geologyhound]

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.  ?

[jasong]

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. 

[Heb]

On 4/9/2023 at 12:23 AM, VicR said:

Could be a Iron Oxide Concretion - they can give that layered effect.

Thank you does actually look quite similar!