Thread: An unknown stone.

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[IMG][/IMG] here is a fairly hard stone,not soft Arkansas hard but it does not auto slurry at all. The slurry is chalk like in colour and feels smooth under a razor. Without pressure it cuts slowly ,with pressure it cut moderately fast. It does not chip out the edge at all. Dimensions are 8 inches long,2-1/8th,s wide,5/8's thick at the thinnest. It has saw Marks on all sides. The brown stains are old oil I am still removing. It is not an ark I do know ,however that is all I know about it. Cheers.

a few more pictures. This stone came in a fitted hand carved box that is western ( region) in feel.

There appears to be horizontal layering on the end view, and the color seems right, so my first limited thought is Hindustan.

Looks green in some photos, is it? Hard to tell from the end photo if it is layering or saw marks.

Perhaps some photos dry, and of the slurry. Did the black mark in the last photo lap off?

Off grey to maybe a little greenish tinge I believe.the last photo is the bottom which is dished a bit,however the dishing is almost machine perfect,really interesting.

Originally Posted by Utopian

There appears to be horizontal layering on the end view, and the color seems right, so my first limited thought is Hindustan.

Could join that guess...thats how mine Hindostan looks...the layers can appear different depending where the stones have been put out...

The lines are also called "Tidal Rhythmites"
http://igs.indiana.edu/FossilsAndTime/Tidal.cfm

It's a nice stone.

that looks similar to a stone i found, what is the approximate grit of a hindostan stone? mine seems to be on the coarse side, maybe 1k though the stone feels smooth to the touch.

A few months ago I picked up this stone at an Antique store, for $8, hoping it was a black Ark.

Tapped it out of the box and sprayed with oven cleaner and scrubbed with Simple green. It does look a bit like yours and I suspect mine is a possibly a Charnley Forrest or Lynn Idwal.

It has been soaking in Simple Green for a couple of months and is still releasing oil, and last time I changed the solution it looked more grey, but once I lap it I believe it will show greenish again.

It is very hard, note the sharp edged chip in photo and produces a thin white slurry. I will get it out of soaking and give it a lap and take some new photos later today or tomorrow.

Just for reference (.pdf dl):

https://scholarworks.iu.edu/dspace/b...pdf?sequence=1