Some natural stone I found.
I found a rock a little while ago (I can't remember where from, but we stuck it in a garden, where it was quickly covered by foliage, I recently re-discovered a large chunk of it), it appears to be similar to shale or slate, I can see lots of small reflections from the rock in the light, and also from the slurry it generates. I'm guessing they're small quartz crystals. I was worried that the reflections may have been from the way I polished the rock, but the slurry has the same reflections (which is a good sign) and dries to a chalky powder (I don't know if this is good or bad or if it doesn't matter).
I cut a piece of it into a rough whetstone to test it on a pocket knife. About 100 laps applying about 1-2 Newtons of force (hey, it's just a SS pocket knife...) gives a shiny edge (I can't tell if it's a mirror finish or not, but it appears to have removed very little steel).
I think I've had enough success with this rock (it does cut steel, and it's definitely >1k) to justify making a proper sized hone from it.
Ask for more information, I can probably find out about it.
Here are some photos of the rock. Click the photos to open full sized images.
http://img35.imageshack.us/img35/6172/s6302563.th.jpg
http://img29.imageshack.us/img29/7855/s6302564.th.jpg
http://img190.imageshack.us/img190/9441/s6302567.th.jpg
http://img132.imageshack.us/img132/2577/s6302569.th.jpg
http://img43.imageshack.us/img43/8454/s6302571.th.jpg
http://img251.imageshack.us/img251/268/s6302572.th.jpg
http://img193.imageshack.us/img193/5...302574y.th.jpg
