Thread: What Stone Is This?

It goes without saying, hack off the spar at the one end and gain yourself a slurry stone for further experimentation.

What would you use to make that cut?

Also, should the stone be lapped with any fluid in particular?

Just lap on water. You can use a hacksaw. Slate is soft. Last time I had a skate with a break like that, I used a coping saw of all things and it still got it done. Just lol the shard off to square it off a bit, grid the surface with a pencil or marker, cancel the grid, grid it again, cancel that one, round off the corners give it a try. For future reference, was way to lap anything not brutally hard is to buy a single granite tile that was polished/lapped and just use that as a base for your wet dry sandpaper. Start at 220 work up to 600-1000 if you want. Anything really hard, you are best off with loose grit silicon carbide on float glass

Originally Posted by Untitled

I have no HCl to test with, can you make it easily?

Yes. Mix salt & hydrogen peroxide but be very careful & google some more about it.

A 325 DMT will lap it, or the 140 if it is really out of flat, but looks fairly flat in the photo, lap under running water, mark a grid on the stone with pencil.

Test it on a razor or knife and compare the scratch pattern to a known grit synthetic stone.

The purple pattern, green molting and flaking on the back look similar to some Vosegine, I have, but you have a lot more green, But it is a possibility, Voaigine slurry’s easily and cuts very fine.

What color is the slurry and do you have photos of the sides and ends?

Cool looking stone.

Originally Posted by Untitled

I have no HCl to test with, can you make it easily?

What would I lap it with assuming it is Vermont slate? I have an Atoms 140 and DMT Diafold from xxc to of. Would any of these be a good choice?

I put limestone in vinegar to eat it away so that way I can get to the fossils inside

Euclid: the first picture posted looks like a Lorraine Rouge...does it look like the other three pictures on the back ?

Euclid,

It is very easy to generate slurry with water, the slurry is quit thin and almost milky and once dried is just a shade off white grains. It turns gray with more grinding, assuming from the steel mixing with it which is removed.

It cuts very fine, almost though I do not have any higher grit synthetic stones other than diamond so I am not sure this would equate to much comparison.

I did take a low alloy steel knife at 59 RC w/ excessively coarse finished and thick/obtuse edge (probably 36 grit belt finish and quickly buffed, 60-70 degrees inclusive) and started grinding away at the stone with water (without flushing the water regularly, just adding enough to keep wet) and light pressure. It came to near to mirror polish with the deep belt scratch pattern removed after about 20-30 min.

The photos I posted show all four long sides, the skinny sides are circular ground smooth and the wide sides are left unground. I will get some pics of the ends tomorrow once I have some daylight to work with for proper lighting.

___________

doorsh,

I suspected this stone I have may be a Lorraine Rouge, which why I came here asking about it after using it and doing some research.

@untitled
I can rule out that your one is a Lorraine Rouge, here are some examples i own...the three on the left...



I would tend to go towards a mottled Vermont or either a Purple Welsh slate which sometimes shows green inclusions, dots or blotches....

Also the fine french (Vosgian Stone, Purple La Lune) stones sometimes show green inclusions..

Think you guys are right on the slate, thanks for all the help…