Yes, BBW's do have layers also. There is almost no information about them. I know that in the old days only a few BBW layers of the Ol'Preu concession were sold as Pierre Lorraines. Ol' Prey is the quarry from Ardennes Coticule. It is rumored that other concessions had less valid blue rock, but that is unconfirmed information. I might setup a survey of BBW layers later on, but there are problems with determining the origin of a BBW, because no one really knows how to recognize them, once they're excavated and mixed together. In a mine, it's easier to keep track of those things, but not so in a quarry, where TNT is used to detonate huge blocks of rock that contain several layers of Coticule/BBW. That's completely different than controlled excavation in an underground mine. As said ol'Preu is a quarry (used to be a site with mining pits, but that's long time ago. Ardennes also has a actual mine at Regné, but they're only very slowly evolving to future exploitation. The BBW's from Regné look much paler. I've only tested a couple of them, months ago when I was visiting the quarry. Rob and Maurice weren't all that certain if it was any good, and they were quite relieved hat I managed to get a dull razor shaving on the test samples.
Obviously, when there's a piece of Coticule attached to the BBW (in case of a natural combination hone) it much easier to make a determination. We're currently working with the research team to come up with standardized procedures to hone a good edge on a BBW. The procedures are actually working, we're just running tests to confirm that they work for a variety of people and that the shaving quality of the edges is pretty much on par with that coming off a Coticule. As soon as these things are confirmed and the procedures validated, we can put a number of test samples to the test, and find out if there's any correlation between whereabouts and/or morphology and honing capabilities.
Another problem with properly testing them, is that measuring honing speed is not that easy. On a Coticule you can go by how quickly that almost white slurry on a pale background turns gray or even black. But with ink-like slurry it's not so easy to monitor what's happening. Ralfson and I are working on an device that measures abrasion speed in an objective manner. If we succeed, it will be much easier to test and compare various hones.
Cheers for the excellent results you got on yours, Kinematic. Thanks for sharing. The Blue of "La Nouvelle Veine". I'll see if I can try one for myself. Sadly, there's not a Nouvelle Veine in the current test group I have at home here. Maybe some of the members that have one can share experiences?
Best regards,
Bart.
Bart.