Sujit,

I would say rock fragment. The ventral surface appears to be highly weathered. Most of the dorsal surface fracture planes are less weathered. The fracture plane on the right side of the dorsal surface appears to be recent. I could imagine that this was protruding from a larger rock or cliff face and got struck off by a falling rock or even snapped off by being run over by a vehicle.

I would also say that you have a rock fragment. On the right picture you can see on the left and right side of the rock specimen structures which look like filled veins (perhaps quartz, calcite or gypsum) along which the specimen broke.

It is weathered artifact rock sample.

Rock fragment. Veins are standing out on the weathered surface. The fragment is too weak to be of real use as a tool.

It is not easy to respond to your question. I have found same tool… From your four photos three seems (1, 3, 4) that was used by ancient hominid and for this they can be named: stone (hand) axe… For this you have to take in consideration the place where did they find it..

Best Regards

I am not an expert, but I am familiar with stone artifacts used by Australian Aborigines. The sample looks weak, but it has broken with almost conchoidal fracture and the top is quite a sharp point. So it may not be so weak. Australian Aborigines made tools by sitting one hard stone on another stone and striking the top stone with a third stone. The result was sharp flakes being broken off the stone in the middle . The sharp flakes were used as utensils. After a while the main stone became too small to be used and was thrown away. That stone is called a core stone. The stone that you illustrate could be a discarded core stone from which a number of sharp flakes have been broken.

These are rock fragments. They are possibly cobbles based on their grain size. They are angular and this may show that they have not traveled a long distance. They are probably close to their source rock. The image on the left contains line which may be a "slickenline" and may indicate fault movement.

The stone fragment was collected from incipient rain gully within colluvium apron (pediment) at the base of small Precambrian residual hill.  The site is known for its rich microlithic assemblage. There is no question of vehicle intruding the site; the sample looks fresh as  photograph was taken after washing. At the moment our understanding is that the sample in all probability is an artifact and a core as commented by Brian P.J.Stevens. We get microlithic flakes in the surrounding area of the same rock type thinly bedded acid volcanic tuff..... we are open to more comments.

I would expect rocks with flakes chipped away to show plumose (feather) structures at the new fracture plane. There's a little bit of it to see at the lower right corner of the second image. But maybe the rock is not fine-grained and/or hard enough to develop those. Tricky. The question is, would you consider this a possible artifact or core if it weren't for the area where you would expect to find some? I would err on the side of caution.

Sujit,

You have not said what is the age of the microlithic assemblages in the area. Disregarding the fresh break, I do not see the patination that I would expect from a Paleolithic artifact that was made out of tufa. Tufa is usually soft enough to weather fairly rapidly. Any scree slopes?

 James,

Thanks for your comments. Our inference as of now is subject to further scrutiny and verification. Attach find a photograph taken in the field, For additional information on the site reference is drawn to our paper already uploaded in RG:

Earliest dates and implications of Microlithic industries of Late Pleistocene from Mahadebbera and Kana, Purulia district, West Bengal. Current Science 107 (7), 1167- 1171

Hi Sujit,

I agree with the response of artifact rock sample, but i think that is not used by the hominid because of the border.

Best regards,

Hakima

That rock was shaped by humans.

I think this may be a rough-out of a stone hand axe. These are produced by striking a larger stone and producing fragments or large flakes of the approximate size and shape of a hand axe. Suitable flakes are then further trimmed to produce a finished hand axe. There is inevitably much wastage and this flake may have been discarded because it was too weathered or soft. There is no sign of secondary working to produce a cutting edge so it is not a hand axe

Dear Dasgupta,

It seems, the sample is a quartzite. It has conchoidal fracture surfaces. The surfaces are by and large look fresh, except in one side which is slightly weathered. Quartzite is a dimension stone and hard and good for preparation of tools. The present stone is having sharp edges. It does not look used for cutting as there is no damaging or blunting of the edges (secondary working). The samples may be transported from other place by human recently and does not appear a paleolith.

Regards,

B. P. Duarah

Dear Dasgupta,

Generally the wind erosion could result this kind of rock faces. Please consider the weather of place that you found it!

Regards,

vahid

We still don't know what kind of rock it is. The shapes suggest worked by humans and the conchoidal fracture on one would suggest chert nodule surrounded by limestone. We have similar such tools in our area as old as 6,000 years.