Search:

Try and get some good close up pics, wet n dry, with slurry and swarf and of the fractured end, perhaps someone can identify it.

Both usually work fine.
Oil do give a finer edge on some stones but it messy to use and it the stone is porous it might be close to impossible to get the oil off.
Try with water first and see what...

No DMT / Atoma?

I've seen both Thuringens and Coticules used for scytes, to do their job they do need really good stones, like the stones used for razors.
I've also seen crappy stones used for them... guess it was...

He means scythe!

Can be very good, you only know when you've tried it.
Flatten it and have a go.... and more pics when you do!