I don't think I have room for both the Saurat 'Genre Levant' and the Loos stone. Which one should I pick, or neither?
@cotedupy I know you have the Saurat; do you also have the Loos?
I'm afraid it's one of the very few types of (documented) western whetstone that I don't have and have never used. I don't see any problem with taking the info from G&H though if you want to include it.
NB - the name 'Pierre de Levant' shouldn't be used in a chart like this, as it can be confusing. I know of at least three completely different types of whetstone (from three different countries) that have all historically been called PdL or 'Stone of the East'.
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Here's a go at some of your list above, I've left off the Japanese ones because even when I have used them - other people will have more knowledge. And also a couple of Swedish sounding things that I'd never even heard of! And added in some other very common types of historic whetstones at the bottom.
- Belgian Blue 3-5k*
- Coticule 600 - 14k**
- Cretan / Turkish Oilstone 2 - 10k
- Dalmore Blue 3 - 5k
- Hard Arkansas 6 - 8k***
- Hard Translucent and Surgical Black Arkansas 15k+***
- La Lune 10k
- Pierre de Saurat / Pyrenees Stone 2 - 6k
- Rouge du Salm 3 - 5k*
- Rozsutec 6k
- Soft Arkansas 800 - 2k
- Tam o' Shanter 6k - 10k
- Thüringian 15k
- Washita 600 - 6k
- Water of Ayr 10k - 14k
- Charnley Forest 8k - 12k ***
- Llyn Idwal 6k - 12k ***
- Welsh Slates (Yellow Lake Oilstone, Glanrafon, Nantlle Valley &c.) 6k - 14k
- Hindustan 3 - 5k
* I wouldn't include both BBW and RdS (or indeed La Lorraine). It's a matter of some confusion as to what might be what, and what's been called different things in different mines at different times. They all act similarly enough.
** You don't get all of this range in a single stone. More friable cotis can have a significant range, but it's never this large.
*** Arkansas and other hard novaculites are extremely difficult to rate in this way. If you raise an atoma slurry on a translucent ark / Charn / Idwal it will abrade like a 1k synth. If you use a burnished surface they'll finish as high as any natural whetstone, and in the case of trans and black arks - higher than anything else.
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Coupla other things to note...
While I have a good amount of experience with the stones above (most of which I've had dozens of example of), I'm certainly not claiming my analysis of their 'grit rating' is any more valid than anyone else's. People interpret different stones in different ways, and use them in different ways.
For instance my ratings above refer to what I think about
edge finish levels, and a lot of them for razor finishing, which happens with next to no pressure. And very few of those stones would ever get used for polishing in the way that Japanese stones do. On the other hand Ed T has given more bias toward the
polishing level of the Jnats he rated, and that's going to come out slightly lower than an edge finish rating. There are jnats that will happily finish the edge of a razor at the 15k level I've put Thuringians at.
The reason for that difference is complicated, but I'd just emphasize again what I said previously on this thread: Hardness or friability of natural stones is an
overwhelmingly important factor, both in terms of polishing and edge finish. It's considerably more significant than particle size.