Paleo knife?

[Atlantia]

Originally Posted by spiral

I must say on a purley factual level some stone age tools were of sedimentry rocks, I guess people on occasion used whatever was to hand.I agree the were not the tool or weapon of choice of course though.

But having seen many thousands of admitadly mostly mesolithic tools dug & itemsed, as well as having owned & studied the personal collection of an archaelogist that was aquired & dug from m 3 continents mostly between the world wars, I tottaly agree with evryone else this is a possibly frost & or certanly mechanichly damaged & water rolled stone, shaped by the forces of nature.

Many Victorian archaelogists fell for their charms as well, there often called Eoliths.

Some still believe in them. Ive even wanted to myself on one occasion.



spiral

Hi Jonathan

Axes and the like, I've seen (had) made from softer materials, greensand etc, but they're often ceremonial or status pieces.

Not knives though, unless it's something like Obsidian (and volcanic glass isn;t the same thing of course)
Although my experience (as that of most I guess) is based on the far more plentiful later stone tools, dating through to the EBA.
I've still got a box of flints somewhere, only a few that are still to hand:

[spiral]

I agree Gene, Ive never seen a sedimentry knife, I took the butchering comment to mean something heavier, but thats my error perhaps...

I am away for a couple of days but we must talk about flints sometime, they were my speciality & obsession for a long time. {I prefer the one on the left.}

Spiral

[Rust Collector]

This object is NOT made of soft rock or sedimentary rock! It passes the steel test. I Believe it to be a chert.

[katana]

Hi
Chert is a form of sedimentary rock. Notice the whitish flecks (inclusions). Chert varies both in colour and hardness.


" .....Chert is a microcrystalline or cryptocrystalline sedimentary rock material composed of silicon dioxide (SiO2). It occurs as nodules, concretionary masses and as layered deposits. Chert breaks with a conchoidal fracture, often producing very sharp edges. Early people took advantage of how chert breaks and used it to fashion cutting tools and weapons......"

Cryptocrystalline is a rock texture made up of such minute crystals that its crystalline nature is only vaguely revealed even microscopically in thin section by transmitted polarized light. Among the sedimentary rocks, chert and flint are cryptocrystalline.

A microcrystalline material is a crystallized substance or rock that contains small crystals visible only through microscopic examination

Judging, again, by the pictures there seems to be inclusions which are not crypto/micro crystalline. Perhaps some clear close-ups might help of the rock surface and percusion / pressure flaking areas.

Kind Regards David

[VANDOO]

THE MATERIAL SHOWN LOOKS LIKE A POOR CHOICE FOR STONE TOOL OR BLADE BUT SOMETIMES THEY NO DOUBT USED WHAT WAS AVAILABLE. THE MATERIAL REMINDS ME OF THE BRICK IT IS LAYING ON.
I HAVE SEEN TOOLS MADE OF BRICK, BROKEN POTTERY, GLASS,QUARTZ, SLATE, LIMESTONE AND VARIOUS IGNEOUS ROCKS. SLATE AND OTHER SEDIMENTARY ROCKS ARE USUALLY SHAPED BY GRINDING OR PECKING AS THEY DON'T FLAKE WELL.
PERHAPS SOME OF THE SOFTER ROCKS WERE USED FOR TEACHING TECKNIQUES TO BEGINNERS. NO DOUBT AN EXPERT FLINT KNAPPER PREFERRED GOOD MATERIAL BUT NOT EVERYONE WAS BLESSED WITH A GOOD SUPPLY OF OBSIDIAN OR FLINT SO THERE IS A WIDE VARIETY OF ODD ARTEFACTS OUT THERE. GOOD FLINT OR CHERT OR OBSIDIAN WAS WIDELY TRADED IN NORTH AND SOUTH AMERICA.

LOOK AROUND FOR A POINT SHOW (ARTEFACT SHOW) IN YOIUR AREA AND SOMEONE THERE SHOULD BE ABLE TO GIVE YOU SOME GOOD INFO ON IT. GOOD LUCK

[David]

Originally Posted by katana

Chert is a form of sedimentary rock. Notice the whitish flecks (inclusions). Chert varies both in colour and hardness.

Well so much for my high school geology education...

[Rust Collector]

Sorry it took so long to get back with better pictures... I've been having trouble getting as close up as I wanted but I think I've go some that illustrate my points. If nothing else this thread has given me an appreciation for the great photography that I see all the time on this forum and the idea that I need a better camera.
I am more convinced the material is chert, it is riddled with crystal occlusions, fractures concoidally and seems to meet the rest of the charataristic associated with it.

[fearn]

I'm having trouble seeing the conchoidal fractures. Atlantia's post in #7 shows them quite clearly. Conchoidal fractures are what one sees when glass breaks. Is there a way you can indicate where you are seeing conchoidal fractures?

As for cryptocrystalline (crystal structure too small to see), I see crystals, and I see lots of evidence (the holes along the edge, for one) where there are fairly large crystals.

F