Originally Posted by
RezDog
It is possible that those inclusions could be quarts. Quartz is a crystal type structure and should be obvious under a loupe. Maybe you can lap past it. However I have never seen quartz as part of a softer rock. There is a high likelyhood that that is a very hard rock and will be a bear to lap. Start lapping it and see where it goes. You will never know unless you try. I have stacks and stack of hone shaped rocks at home. I have little education about rocks and have just learned by trial and error.
My latest test specimens have produced one mid range, fairly fast hone and a couple of other I would call prepolishers. They produce Shana Le edges but not really the quality I’m looking for. As always, keep your eyes open.