...or a buddy who worked at a quarry in Belgium or Japan or anything.
Funny thing. I have a quarry on the property. More like a "dig" I suppose, as we live on a range of mountains that is basically glacial till. We took almost all the rock out of it that went to build our stone hearth, exception being some round river stone that our mason used to edge a couple places. He said it was nice not to have to haul a tonne of rock to the jobsite every day. Don't like that one? We got lots more...
The place is called StoneGround Farm, "...because that's the only kind of ground we have."
Most of my hones for keeping tools sharp come from the quarry. Somewhere there was a layer of hard blue fine grained stone, because I find a lot of tabular pieces about 1.5 inches or so thick. Lovely for keeping a point on punches, edges on chisels, sharpening axes and striking knives and scythes and shovels etc.
I also have a greenish coarser stone and some other blue that is almost quartzy. Cryptocrystalline. Mostly it's a jumble shop and I just pick up the interesting ones as I run across them, and pile them by the shop. Pretty sure none of it is fine enough to put a good edge on a straight, though.
O.H.