What would you compare a Dalmore to, finish wise? I keep getting conflicting information about where it sits "grit" wise. One a scale of soft Ark to Translucent? Someone needs to create some sort of scale for natural stones.
Yeah, you do see people putting them quite high, but ime I'd say 4-5k normally. They do vary a bit so maybe 2-6k at the extremes, but you wouldn't get that whole range in a single stone. Really good kitchen knife edges, but you're not going to finish a razor on one. With a decent slurry raised you could probably set a bevel without too much faff, if it was in alright shape to begin with.
Indeed, a scale might be handy, I might have a go at that at some point. TBH I don't hold much truck with the idea that you can't rate the 'grit level' of natural stones. If you've used enough synths it's perfectly possible to compare the speed and finish of them to give an idea of what something's going to do.