Natural Stone Question

[danny13]

got my first natural stone. I understand there may imperfections on it but what are your thoughts on this? Is this acceptable, and something that is common? I was hoping for a nice flat smooth surface to finish on, but not sure if this is part of what is to be expected.

 

[ethompson]

Not uncommon at all. Su pockets (hence the name suita) like you see there are relatively common and often not something to worry about - I got in a very expensive hunk of stone yesterday that has little pockets like that on the surface and I still consider it one of the best stones I've ever gotten my hands on. If you want a flawless jnat expect to spend a ton of money for rapidly diminishing returns.

 

[aporigine]

got my first natural stone. I understand there may imperfections on it but what are your thoughts on this? Is this acceptable, and something that is common? I was hoping for a nice flat smooth surface to finish on, but not sure if this is part of what is to be expected. View attachment 336945


View attachment 336946

Curious. What stone?

 

[Legion74]

Holes are ok and shouldn't effect the honing. Inclusions and chunks are what you need to look out for and avoid.

 

[brownsugar69]

is it even a JNAT if it doesn't have a corner missing or so

 

[JPAU]

Holes are ok and shouldn't affect the honing. Inclusions and chunks are what you need to look out for and avoid.

aside from a bbw, I do not own any natural stones and am genuinely curious. I would like to understand the distinction between ‘holes’ and ‘inclusions’ and ‘chunks’ - they all evoke divots, picks, small recesses etc. to me although these are probably terms of art in this context.

 

[stringer]

aside from a bbw, I do not own any natural stones and am genuinely curious. I would like to understand the distinction between ‘holes’ and ‘inclusions’ and ‘chunks’ - they all evoke divots, picks, small recesses etc. to me although these are probably terms of art in this context.

Sometimes if there is a toxic (causes unwanted scratches or burnishing) inclusion or chunk or pocket or line you can dig it out, creating a hole or an empty line. And then you can proceed to use it. And sometimes what is toxic to a polisher or a razor sharpener is a big shoulder shrug to anyone else.

 

[JPAU]

Sometimes if there is a toxic (causes unwanted scratches or burnishing) inclusion or chunk or pocket or line you can dig it out, creating a hole or an empty line. And then you can proceed to use it. And sometimes what is toxic to a polisher or a razor sharpener is a big shoulder shrug to anyone else.

This geological world is fraught with danger and seems to require considerable time investment to understand. Thanks for explaining. Think I’ll just hang out for a nice koppa at a decent price to try a natural out! Thanks to @danny13 - already learned a bit from this thread

 

[Legion74]

aside from a bbw, I do not own any natural stones and am genuinely curious. I would like to understand the distinction between ‘holes’ and ‘inclusions’ and ‘chunks’ - they all evoke divots, picks, small recesses etc. to me although these are probably terms of art in this context.

An inclusion, or at least a toxic inclusion might be something like a chunk of quartz, or a pocket of sand. Something hard enough that it might chip the edge when it hits. As Stringer said, often you can just dig it out with the tip of a knife, leaving behind a little hole. The hole is ok because the edge just goes over it without damage.

But often where there is one toxic inclusion there may be more under the surface, so you need to be wary. Natural holes are not an issue. They might have just been bubbles, or soft material inclusions when the stone formed, and they just wore away leaving a little void.

 

[JPAU]

Thanks! Learning a lot! By toxic don’t mean that there is a vein of material that is chemically corrosive or something?

 

[refcast]

@JPAU

Toxic isn't really quite apt. . . It's more of impurity? It's harder, coarser material like quartz. It wears down more slowly than the rest of the stone, or releases chunks.

 

[aporigine]

Think of it as toxic to the knife’s edge or finish.
Not much greater heartbreak than a stone that is 99.99% uchigumori and 0.01% (nails on a blackboard.)
(distributed throughout and not fixable by digging.)

 

[JPAU]

I have to stay away from these discussions - you’re dragging me down the deep dark tunnel with you. I barely get the opportunity to use the stones that I have as my knives are all sharp, and I don’t think that I would survive the prospect of polishing …

Sorry to hijack the thread

 

[Legion74]

Thanks! Learning a lot! By toxic don’t mean that there is a vein of material that is chemically corrosive or something?

In this instance, toxic just means bad, or damaging.

As opposed to, say... a manganese splotch on a coticule, which is just cosmetic and does nothing to the edge.

 

[stringer]

Here's some examples

 

[Dr. Knives]

got my first natural stone. I understand there may imperfections on it but what are your thoughts on this? Is this acceptable, and something that is common? I was hoping for a nice flat smooth surface to finish on, but not sure if this is part of what is to be expected. View attachment 336945


View attachment 336946

This is fine. common and acceptable. also depends on how much you paid for it. If it bothers you or releases grit, you can always dig it out. Should not be a major problem