Thread: Rock diving

If you asked 90 of 100 geologists about hones they probably couldn't even spell the word hone. You need to find a petrologist (a rock guy) who then specializes in economically valuable rocks and then further specializes in hones. it's like going to a doctor and trying to find someone who specializes in a very rare disease. Probably there aren't more than a few in this country, maybe. it's like that.

You don't need a degree to dabble in hones. You just need to go to a good Library and read up on hones and learn what types of minerals comprise good hones . Then you pick an area to investigate and get a geologic map and a topographic map and then you overlay the two and then you go out into the field looking for outcrops. it's that simple-har har.

But seriously, that's how you do it.

Originally Posted by thebigspendur

You don't need a degree to dabble in hones. You just need to go to a good Library and read up on hones and learn what types of minerals comprise good hones . Then you pick an area to investigate and get a geologic map and a topographic map and then you overlay the two and then you go out into the field looking for outcrops. it's that simple-har har.

But seriously, that's how you do it.

Most if not all hones/sharpening stones have some form of silica as the cutting particle, and a type of silica called chert is the one you are looking for especially the form called radiolarians. Radiolaria are the silica based shell casing of a prehistoric sea animal, it is still silica but its a very fine particle form of silica. Arkansas stones are chert but of a monolithic form, all solidly bound, Japanese naturals have chert particles that are individual and mixed in with clays to created a chert grit particle that acts and cleaves as it cuts. You can search geology maps in your area for ancient sea beds that are rich in radiolaria. Just one idea.


Alx

Originally Posted by alx

Most if not all hones/sharpening stones have some form of silica as the cutting particle, and a type of silica called chert is the one you are looking for especially the form called radiolarians. Radiolaria are the silica based shell casing of a prehistoric sea animal, it is still silica but its a very fine particle form of silica. Arkansas stones are chert but of a monolithic form, all solidly bound, Japanese naturals have chert particles that are individual and mixed in with clays to created a chert grit particle that acts and cleaves as it cuts. You can search geology maps in your area for ancient sea beds that are rich in radiolaria. Just one idea.


Alx

Finished spending a week at a friends beach house and one of the dinner guests every night was a geologist from one of our better known Northeastern universities. As others said here, he knew very little about hones (but the dept has a GREAT machine for lapping and polishing stones that I want to get my hands on). He also made the same point that Alex makes above about Silica.

One other thing he said is that stones don't smell. This shocked me as I have a Kiita with a particular slatey aroma that I love. We ended up arguing about what it meant for a thing to have a smell. Ended in a stalemate.

Originally Posted by Oakeshott

One other thing he said is that stones don't smell. This shocked me as I have a Kiita with a particular slatey aroma that I love. We ended up arguing about what it meant for a thing to have a smell. Ended in a stalemate.

I would have liked to be a fly on the wall for that conversation.

This has turned into an interesting thread, before when I mentioned taking a geology course it was not to learn the ins and outs of how to find cool new sharpening stones, just that in starting down the road of HAD, I have become very interested in rocks in general. Living at the top of an escarpment and having several quarries around me (new and old) I see a lot of stone.

Last weekend I did a walk along a portion of the Bruce trail (look it up if you don't know what it is) and the area was Lime house. Back in the day they mined Limestone. Along the trail were some old Kilns and storage shelters for the explosives they used. It was a neat place to visit.

Well that’s really an interesting discussion.
Me personally - I live in the slate mountains of the Rhein-Main region in germany. When I found out several years ago - as I started to get interest in thuringian whetstones - that these stones exist of slate in a special composition ( I know, a lot of people here didn’t like to hear this, as former discussions already pointed out) I simply went out the door, stepped in the woods next to my house and took some slate samples. After cutting, lapping and polishing of the stones I was eager to see how they perform –honing a knive - and I was very disappointed because nothing happened. Well not really nothing, but not what I expected or hoped. Some scratches on the edge, some abrasive effects of course, impurities of iron and quartz that destroyed the edge. I took some other samples from other places, different slate stones and also other stones, with some minor success but in no case anyway comparable to thuringian slates.

The thuringian whetstone quarries in general – and I am not talking about the water whetstones in special - are well known since the middle ages or even earlier ( the celts also used sharpening stones from this region 400 - 200 B.C.). And there are a lot of quarries with different stones, different capabilities and very different grit sizes, coarse stones for whething scythes, stones for sharpening kitchen knives and very fine stones for honing razors, scalpels and fine instruments.

When the engineer Rudolf Schwarz took over the J.G. Escher Sohn company around 1920, he was faced with the fact, that the whetstone makers and companies in the Steinach area, who had delivered the Escher company for many years with waterwhetstones, started to distribute the whetstones by their own companies and did not deliver the Escher company any more. So he had to find new quarries to satisfy the demand for waterhetstones which was still quite high at this time.
He did this by exploring the thuringian slate mountains together with one of the leading german geologist at this time for month to find good and exploitable quarries. Finally he found at least two new quarries which were able to cover the demand of whetstones till the end of WW2, when artificial stones started to prevail over natural stones.

So the abrasive effect compared with a certain size and form of the abrasive components as well as the purity of the stones or let’s say better the absence of hard impurities is what makes a good whetstone.

The slate or mud slate in the case of thuringian whetstones was build as deposit of a deep, silent see millions of years ago. And of course very special conditions were needed at the time the deposits began to sediment and the stones were formed. Beginning with the existing biota at this time, salt content of the water that covered the mud, temperature and pressure during the formation process of the stones and a lot more.
These very special conditions are only given in very exceptional cases and that’s what finally differs good and capable whetstone material from the rest.

Originally Posted by alx

Most if not all hones/sharpening stones have some form of silica as the cutting particle, and a type of silica called chert is the one you are looking for especially the form called radiolarians.

Alx

So I got curious about my area - nothing more than shale, mudstone. But looking about 2.5 hours NE of me.. I noticed a fair amount of chert deposits in the SE Oklahoma region... might have to get a day trip planned!

It's true, rocks don't smell. What you do smell are the remnants of soil and mold and mildew all all the other stuff that lives in the ground that comes into contact with the rock and remains there who knows how many years until you get it.

Originally Posted by thebigspendur

It's true, rocks don't smell. What you do smell are the remnants of soil and mold and mildew all all the other stuff that lives in the ground that comes into contact with the rock and remains there who knows how many years until you get it.

Yes BigSpender
I agree with you. Arkansas hard stones do not smell because they are nearly 100% silica, and a very fine type of silica at that. Japanese stones smell because of the binder or clays that make up the body of the stone. This clay was part of the original event that provided the material including the radiolaria, so the clays are integral to the character and nature of the stone. Some japanese sharpening stones have been dug from such a deep level that many of the clays have either been squeezed out or through pressure and the resulting heat transformed, metamorphed into a harder stone. These can still be used by are not so what I call "user friendly".

If you could find natural stones with the grit particle of the arkansas stones, but slightly softer you might be on to something. Oh, also you might look for deposits of material that is associated with sharpening stones, like Kaolin used for making porcelain.

hope this helps, Alx

Originally Posted by thebigspendur

If you asked 90 of 100 geologists about hones they probably couldn't even spell the word hone. You need to find a petrologist (a rock guy) who then specializes in economically valuable rocks and then further specializes in hones. it's like going to a doctor and trying to find someone who specializes in a very rare disease. Probably there aren't more than a few in this country, maybe. it's like that.

You don't need a degree to dabble in hones. You just need to go to a good Library and read up on hones and learn what types of minerals comprise good hones . Then you pick an area to investigate and get a geologic map and a topographic map and then you overlay the two and then you go out into the field looking for outcrops. it's that simple-har har.

But seriously, that's how you do it.

You sure seem to have a lot of knowledge on this topic. Fancy a name change to "thebigrockdiver"?

The rocks i ben getting out of my yard all make my darn hands smell like sea weed.
I recommand looking in know dumbing grounds for rocks like under their dreks.
My one neighbor must think i a bit crazy.
I heard her say he spent all that time flatting a rocks just to sharpen a axe.
why not just buy a stone.
Cause when i sharpened the double bit axe by sticking in a peice of wood so i was outside.