How to recognize toxic inclusions?

[Pawel pksa]

I know, there is another thread inviting uses to post pictures of the toxic inclusions, but rather not active.
So, in general, how to recognize if the inclusion is toxic or not?
Some beautiful stones come with various inclusions which attribute to their beauty, but are they poisonous?

Just an example

 

[bluesman 7]

By inspecting the edge or by the feel of the edge as it passes the inclusion.

Toxic inclusions are somewhat misnamed because the toxicity has nothing to do with peoples health, but of what they do to the edge being sharpened.

 

[MasterOfPups]

I doubt you can tell without running metal over it and check for scratches. I like to use a kiridashi or the back of a chisel first.

 

[alex1921]

Listen, feel, inspect using magnification.

 

[Pawel pksa]

You see, apparently it is my ignorance. I thought is is about hazard for people, while you say it is rather about hazard for the blade. Clear. Then obviously it can be detected while honing. Yes, indeed it happens with suitas or other stones, even slates. Thanks. But why they call it toxic, misleading.

 

[cotedupy]

^ What others have said ^. It's only really when trying a stone that you'd tell (and you'll feel it immediately - you don't need to be an expert).

What you're not going to be able to tell really is if any of those suji/lines will be toxic in the future as you go down a stone. And might require some digging later.

On sight alone - your stone looks pretty good tbh. The parts I might be pay closer attention to is the thicker bit of the diagonal line in the top right of your pic. And the line across the middle with the part that looks like two dots next to each other, near the base of your thumb.

But basically - if you can't feel anything bad, then you're grand

 

[stone and strop]

But why they call it toxic, misleading.

Its not misleading.
It is toxic to your blade. We are talking honing here, not personal health.
This thread is in the Honing section (related to honing)

 

[jj_sharp]

Many on forums seem highly concerned with toxicity.

I have used new transmission fluid for honing oil. Others think that is a bad practice, too risky. I don't drink it.

I knew a guy that would not eat game taken with lead shot. That left me scratching my head in wonder.

At work, I may be the only person that drinks tap water, and I don't know why that is. Half of the refrigerator space is taken up with water bottles. Is Florida tap water dangerous?

 

[timwcic]

Is Florida tap water dangerous?

Been drinking two gallons a day of St. Petersburg’s finest tap water for decades. I am still a PITA

 

[cotedupy]

Its not misleading.
It is toxic to your blade. We are talking honing here, not personal health.
This thread is in the Honing section (related to honing)

Kinda misleading tho... as 'toxic' and 'poisonous' are synonyms, and jnats are mainly used for sharpening or polishing kitchen knives.

I'd call it a misnomer anyway!

 

[RayClem]

Many inclusions in hones are minerals that are softer than steel. Examples are calcite, flourite, and iron oxide. However, if the inclusions are minerals that are harder than steel, then they can be a problem. When testing a new hone, always do so with an inexpensive razor such as a Gold Dollar. They are great for developing honing technique and evaluating hones.

 

[bluesman 7]

Kinda misleading tho... as 'toxic' and 'poisonous' are synonyms, and jnats are mainly used for sharpening or polishing kitchen knives.

I'd call it a misnomer anyway!

The word poison is used quite a bit without regard to something actually harmful to ones health. For example a chemical reaction can be poisoned with the addition an otherwise benign compound. In chess we have poison pawns that can be taken but are often better left standing.

 

[jj_sharp]

Been drinking two gallons a day of St. Petersburg’s finest tap water for decades. I am still a PITA

It would appear that you are across the bay.

Just this morning I was filling my water jug at the sink, and a fellow employee said: "There is bottled water in the refrigerator..."

I literally may be the only one out of ~18 that drinks from the tap. But one of them is reallly big on recycling...including her spent water bottles.

 

[Gamma]

Other synonyms for toxic are dangerous, destructive, injurious and unsafe.
Toxic people aren't poisonous, but still toxic; not every 'definition' is going to fit perfectly.

Toxic inclusions are called such because you can, literally, destroy hours of hard work with a single pass over a metallic particle poking out of an otherwise soft seam in a Karasu or whatever. Thuringian hones (like Escher) can, sometimes, have pyrite inclusions that will also destroy an edge.
For me, the term 'toxic' in 'toxic inclusion' is perfect.

FWIW - an inclusion that 'proves' to be safe now might turn out to be 'toxic' later on. Visual inspection can only yield little more than a guess. There is no way to know what lies below the surface. Sometimes you get a heads-up warning, other times you just get a chip in the edge.

 

[Frank Shaves]

I just assumed that a toxic inclusion was an inclusion that over time could undermine the integrity of the stone. I'm glad I read this thread!

 

[cotedupy]

The word poison is used quite a bit without regard to something actually harmful to ones health. For example a chemical reaction can be poisoned with the addition an otherwise benign compound. In chess we have poison pawns that can be taken but are often better left standing.

A fair point. But given that it's primary meaning is something that's injurious to health when ingested, I'd contend that there are less confusing words that might have been used in regards to something associated with cutlery. Pavel's far from the first person to have made this mixup.

It is what it is though, and at least it's not the other way round eh! With certain stones having deadly poisonous streaks through them, but we all just called them something completely harmless-sounding.

 

[Pawel pksa]

I come from ceramics and pottery domain. There we deal with various minerals when composing custom glazes, also when preparing custom clay mix. And I tell you, toxicology in there is very important. The danger is more in inhalation than in swallowing. There are various safety sheets, hazard tables or just list of poisonous rocks - just search in internet.

Why I says so here? The minerals are in most cases the milled rocks. The danger comes when polishing and cutting the rocks. But not only, some contain gases and other hazards. But of course, the most toxic substances come from these nice colorful fractions of rocks. Does it happen for hones? I have no idea. What about cutting and flattening the stones? I don't know. Does the lack of awareness of this issue effect the wet shaving community. Yes, definitely. The first example is the common use of chromium oxide, especially when being self prepared from the pure powder.

So for me yes, the naming here is simply wrong. In my perception, "toxic" term is precise, also when applied to rocks/stones. Is that so important? Not so much, probably nobody will die, but the safety aspects shall be unbiased by rule.

PS
@Gamma piryt might be also very helpful, take La Lune.

 

[RayClem]

I come from ceramics and pottery domain. There we deal with various minerals when composing custom glazes, also when preparing custom clay mix. And I tell you, toxicology in there is very important. The danger is more in inhalation than in swallowing. There are various safety sheets, hazard tables or just list of poisonous rocks - just search in internet.

Why I says so here? The minerals are in most cases the milled rocks. The danger comes when polishing and cutting the rocks. But not only, some contain gases and other hazards. But of course, the most toxic substances come from these nice colorful fractions of rocks. Does it happen for hones? I have no idea. What about cutting and flattening the stones? I don't know. Does the lack of awareness of this issue effect the wet shaving community. Yes, definitely. The first example is the common use of chromium oxide, especially when being self prepared from the pure powder.

So for me yes, the naming here is simply wrong. In my perception, "toxic" term is precise, also when applied to rocks/stones. Is that so important? Not so much, probably nobody will die, but the safety aspects shall be unbiased by rule.

PS
@Gamma piryt might be also very helpful, take La Lune.

If you go back over 50 years, you will find that a lot of pottery glazes and paints contained toxic pigments. Two common ones were cadmium yellow and lead white. Then there are the original Fiestaware pottery colors that contained uranium oxide that makes the colors vivid, but also radioactive. The newer editions of the pottery are not radioactive.

 

[Pawel pksa]

[mention]rayclem [/mention] That is correct, not pleasant but real. But the main danger was for potters, not the users. ....unless you keep their acids like lemons, vinegar etc. Ancient Romans also were transporting water in lead pipes. In many countries the roofes were covered with cemento-asbestos. Famous “Radium Girls” were painting clock dials with self luminous paints.

 

[RayClem]

[mention]rayclem [/mention] That is correct, not pleasant but real. But the main danger was for potters, not the users. ....unless you keep their acids like lemons, vinegar etc. Ancient Romans also were transporting water in lead pipes. In many countries the roofes were covered with cemento-asbestos. Famous “Radium Girls” were painting clock dials with self luminous paints.

It was not just the ancient Romans who used lead pipes. Back around 1970, I worked one summer as a plumber's helper. One job we did was to replace some lead pipes in a home that had been built around 1900.

Back then, there were no PVC drain pipes so we used cast iron pipes sealed using oakum rope and melted lead. The oakum was packed down into the joint. Then a lead ingot was melted in a steel ladle and the molten lead was poured down into the joint to seal it.

We also used lead solder to join copper piping. Now such solder is prohibitted for plumbing.

And back then, thermometers we used to check body temperature used mercury. There were also "quiet switches" that used mercury tilt switches. Thermostats also had mercury contacts.