^ The slate dagger roughly shaped, using aggressive quartz and granite grinders.
^ Tools to be used to finish the edge.
^ Round stone being used to grind off the "ridges" that were left behind by the coarse shaping, where the budy of the blade transitions to the cutting face. You can see on the lower edge the sharp ridgeline. Shaping with the aggressive tools left a more or less flat face, while the end product will be convexed.
^ Another image showing the areas being focused on. The upper edge is almost done, the lower is barely touched.
^ Cutting faces convexed.
^ Beginning to sharpen the edge with a slate hone. Pressure has to be applied to the back of the edge while grinding the front, or splinters and chips will be knocked off. As ever with slate, there is no burr, so you can grind in whatever direction seems easiest.
^ It takes a very long time to get the edge sharp the first time! Are we having fun yet?
^ A finished edge straight off the hone. The chip has been there pretty much since the project started, it would take far too much time and too much life out of the blade to fully remove it.
Though it is a finely formed edge, the total angle is fairly obtuse. I have some points that are basically paper-thin, and extremely sharp, but they are too fragile to use for most work. This dagger is intended for more all-around use and was made fairly thick for strength. But even with a chunky "tough" edge...
^ ... damage quickly accumulates if the blade is mistreated. This is the result of aggressively pull-cutting one handful of dried grass. Slate edges respond well to delicate slicing and sawing, and respond poorly to being forced through the material.