Thread: How do you test an unknown natural stone?

Got this stone on eBay. Would like to know how some of you go about testing an unknown stone. I think it's a Turingian. I thought of finishing a razor to an 8k, then try the stone and test to see if it improves. Just curious to see what other people do. Thanks in advanced, Double O

If you think it is a finisher I would do just what you are thinking. That way you can tell if it improves the edge or not. If you have higher finishers or another Thuringian you can use it after one of those. Might be able to tell you if its higher than an 8k, but less then a naniwa 12k for example. Atleast that way it will give you an idea where in your progression it would go. Atleast that is what I did when I got a mystery stone that I thought was a Thuringian. I'm still not sure, but I have an idea where to place it.

I'm with you Double0, lap it , 8K your razor, then work it on the new stone.
I would do it in cycles of 20 strokes, shave test in between cycles.
Worst scenario, it's a PHIG's relative & you got a lot of cycles to do.

And try take some close up pics of it wet/dry and with slurry as you are using it!

As I do it:
- Clean it by placing it in a bowl of water with a machine washing-up tablet at 70 degrees Celsius. Slow heating during one hour.
- Make the stone plane in the usual way.
- Determine the hardness with a DIY Sclerometer (See: Grinding and Honing Part 2 pages 34-36 http://bosq.home.xs4all.nl/info%2020...ing_part_2.pdf)
- Test the fineness with a teaspoon and compare it to a standard.
- Determine the color and drawing and compare it with known stones.

Say What ????........

I don't like licking used stones. I always cook them. I hope to live many years to come!
After flattening them and looking to the slurry, I smell.

And most importantly look and comapare with available examples and pictures if you want to know the name.

Tongue test. Best way to determine.

The other unscientific way I use it to determine how quickly it'll absorb water compared to other hones. Faster, lower grit.

...or you send it to me!