Thread: Deeper Petrographic / Geological Researches of razor hones and sharpening stones

I wanted to report another Update for my researches. As many of you might now iam still in the search of the fine french razor hones beeing sold under the "La Lune" and "Special Stone only for Good Razors" Trademark. The comapany behind it was F.G.B.C....

I did contact a geologist from an University to further more research some samples of razor hones / sharpening stones under a deeper petrographic / geological point of view. This means thin cuts (cuts of the stone 30microns thin) plus a analysis with the petrographic microscope. Eventually SEM shots could be done...thats open till now...

My counterpart till now was really open minded and seems to be in generally interested into this topic. So till now this is only a short report but i hope this will get a deeper cooperation !

You all know that iam doing this stuff in the main focus as "community" projects so i also would like to ask as many people as possible to further more define Questions which might be relevant for this topics....i will try to further more explain later what the different researches are in detail good for.

Stones under focus:
Those are the stone samples which are actually in focus or in which iam intersted in to get some thin cuts done and get more details of the composition of abrasives. I also would like a professional analysis of which type of material we talk under a geological point of view. Often we have terms like slate, mud slate, quartzites, etc. which could be just a better "guess" then a professional interpretation.

#1 Special Stone for good Razors
Estimated type: slate/glimmer slate
Color: metallic gray/blue

#2 Pierre La Lune Violet
Estimated type: slate/mica slate
Color: red-violet with green inclusions

#3a SchwedensteinEstimated type: Slate/Mud Slate
Color: brown-red-green

#3b SchwedensteinEstimated type: Slate/Mud Slate
Color: gray-black

#4 Vermio Slate
Estimated Type: Slate/Shale
Color: dark black

#5 Thuringian Water HoneEstimated Type: Slate/Mud Slate
Color: grey-green

#6 Orange Shale
Estimated type: Quartzite?
Color: Orange

#7 Khao MenEstimated Type: Slate / Mud Slate
Color: dark black

#8 unknown Estimated Type: Quartzite ?
Color: beige/orange

#9 unknown StoneEstimated Type: Slate
Color: brown-bronze with green and red inclusions

#10 Bavarian FrankonianEstimated Type: Quarzite
Color: beige-yellow-grey

#11 & #12: Japanese Whetstones

Questions:

1. What do you think are the main factors to get a connection between honing properties of a stone and the geological interpretation in terms of thin cuts ?

2. How important is the analysis of "abrasive particle" content and "form of the particles" ? How important are other materials without any abrasive content ?

3. Youre Questions ? Anything you wanne add i should ask a geologist for in connection to natural sharpening stones ?