Laguna Obsidian Clay Body - Manganese Toxicity to Plants?

[Colorado]

I picked up some Laguna Obsidian clay recently to make some black pots. However, the person at the store informed me it should not be used for food contact due to high levels of manganese in the clay body.

This got me looking into the manganese toxicity issue of this clay and there appear to be reports of toxicity associated with the firing and perhaps even just working with bare hands with the clay, if abrasions on the skin are present to allow entry into the bloodstream.

It seems to me that if there is a risk of manganese leaching into food even after firing, perhaps there is a risk that it could leach into the tree through the roots. On the other hand, I would think that the firing process would largely stabilize the material.

Is this a concern? Any problems with using high-manganese clays for bonsai containers? Thoughts?

 

[penumbra]

I don't know this clay body but I have used a few other dark manganese rich clays over the past 15 years. Maybe you clay is different because there are no issues with mine. My clays are not black but very deep brown. Additionally I have used manganese stains many many times.
I will be following this thread to see what others have to say.

 

[Colorado]

Thanks for the input. To be clear, I haven’t used it yet. Wanted to get some feedback first on whether safe for plants.

 

[HorseloverFat]

I have used 3 Different Dark Brown/Black Clays. It was always just considered that once the body was vitreous, there would be no issue.. This could be wrong.. I, ALSO, am curious what others have to say.

Si-02 Black.

Am 710

And a bit of Dark Chocolate Trail Mix (Georgies, I believe. FANTASTIC!)

I also have @sorce pots made with the 710, it appears, That function, consistently, without detrimental side-effects.

(Sorry.. My new phone has that Groucho button)

 

[HorseloverFat]

I almost bought some of that Obsidian, too, actually, round November.

Laguna has a HUGE palate of Cone 6 Porcelain in unREAL colors.. like pink, teal and turquoise (a scad of 'normal' colors too).. And they also produce it in BLACK...That's what I will be trying next "buy".. buuut I have some clay bodies now.. so it can definitely wait.

 

[ShadyStump]

Thinking out loud, as it were.

It would seem to me that any sort of heavy metal toxicity in plant life would depend heavily on the plant. The single greatest concern in public water treatment here in Colorado is the prevalence of heavy metals, so I would imagine any of our native trees would be well adapted to it.
In fact, I'd suggest that most trees should have little or no problems.

If it's of great concern to you, I'd suggest treating the finished pieces somewhat like cement pots and let them soak for some time in several changes of water to help pull any manganese out of the surface more quickly.

 

[penumbra]

I really have to say I have very little concern about excess manganese in a clay body, at least as it concerns plants. I don't want to start an argument that sounds too woo woo, but in regard to how plants metabolize chemicals, they are a lot smarter than us.

 

[ShadyStump]

Trees aren't trying to move around 2/3 of there live, so they're allot more efficient, which means they can be allot pickier about what they eat or how they use it.

 

[HorseloverFat]

Trees aren't trying to move around 2/3 of there live, so they're allot more efficient, which means they can be allot pickier about what they eat or how they use it.

I understand. Buuuut.. plants in NATURE.. die from the top down...

Long roots extended with spaced out pockets of fine roots... they reach their "capacity" for growth..

Through root trimming/reduction, increased vigor and young new root growth in a smaller area are achieved.

Sooo a Bonsai "done right" can be even "smarter" than a wild tree.. more adaptive.

Y'see'Im'say'n?

 

[sorce]

I read up on the effects of poison from Manganese. (Note Not Magnesium)

I actually was trying to find out if it was an allergic reaction, yet couldn't find anything there, all I could find was how my symptoms added up to regular poisoning.

The physical pains are extreme and the wounds disgusting.
I am quite certain I was mildly hallucinating, since this was around the time I was "conversing with spirits".

It's also what made my heart feel so jacked I quit smoking.

I used that clay, stopped for a couple years, then used it again. The symptoms returned like clockwork. An irregular freaking out over noises, wasps in the basement that were spirits till they weren't. More physical sores and extreme pain.

Could be because I licked it, so I definitely won't do that again, but I've also sworn not to use it without gloves in the future either.

It's that pretty, but f Manganese too, I'm still scared to use it.

I don't fear it outside of handling it unfired.
It's a good general rule to not huff your kiln vapors, but I fear that less than that Manganese clay and have smelled the bleachy smell of vaporized salt. That's poisonous too!

Notes on Frostproofededness and Plant health can be found here.
Post in thread 'Rmj, how much tree to use?' https://www.bonsainut.com/threads/rmj-how-much-tree-to-use.15669/post-759157

FM only stands for Frequency Modulation when it doesn't stand for F Manganese.

Sorce

 

[HorseloverFat]

I read up on the effects of poison from Manganese. (Note Not Magnesium)

I actually was trying to find out if it was an allergic reaction, yet couldn't find anything there, all I could find was how my symptoms added up to regular poisoning.

The physical pains are extreme and the wounds disgusting.
I am quite certain I was mildly hallucinating, since this was around the time I was "conversing with spirits".

It's also what made my heart feel so jacked I quit smoking.

I used that clay, stopped for a couple years, then used it again. The symptoms returned like clockwork. An irregular freaking out over noises, wasps in the basement that were spirits till they weren't. More physical sores and extreme pain.

Could be because I licked it, so I definitely won't do that again, but I've also sworn not to use it without gloves in the future either.

It's that pretty, but f Manganese too, I'm still scared to use it.

I don't fear it outside of handling it unfired.
It's a good general rule to not huff your kiln vapors, but I fear that less than that Manganese clay and have smelled the bleachy smell of vaporized salt. That's poisonous too!

Notes on Frostproofededness and Plant health can be found here.
Post in thread 'Rmj, how much tree to use?' https://www.bonsainut.com/threads/rmj-how-much-tree-to-use.15669/post-759157

FM only stands for Frequency Modulation when it doesn't stand for F Manganese.

Sorce

The body pains.. yes.. BODY pains I received when inhaling 710 dust, accidentally, STRONGLY mimicked food poisoning pains..

I believe I was hallucinating.. buuuut I'm an old Psychonaut with a strong mind... so my doors pf perception are always fairly clean, and my "walls of reality" are intentionally flimsy...

 

[Leo in N E Illinois]

You know, until OSHA rules required fume hoods in chem labs, chemists only lived to about 48 years old. You guys need to stop huffing your clay bodies.

Seriously, once fired, I don't think manganese in the clay body would be a big issue for the tree in the pot. BUT, I do believe it is a problem for a careless potter snorting the dust before it is fired. And there is the question of whether it can be absorbed through the skin, you should read your MSD Sheets, and follow safety suggestions by Laguna.

Trees will have no trouble. especially if there is drainage holes in the pot, and the pots are watered, the allowed to drain. Hence, no build up.

 

[HorseloverFat]

You know, until OSHA rules required fume hoods in chem labs, chemists only lived to about 48 years old. You guys need to stop huffing your clay bodies.

Seriously, once fired, I don't think manganese in the clay body would be a big issue for the tree in the pot. BUT, I do believe it is a problem for a careless potter snorting the dust before it is fired. And there is the question of whether it can be absorbed through the skin, you should read your MSD Sheets, and follow safety suggestions by Laguna.

Trees will have no trouble. especially if there is drainage holes in the pot, and the pots are watered, the allowed to drain. Hence, no build up.

Oh yes.. that was a one-time mistake in methodology..

Now.. if I'm working with clay, any clay, POST-leatherhard.. I wear a KN95..

There's actually a pic of me, masked up, last night, glazing and sandin', on my stoneware thread.

I can't afford to mess around with.. "extra filtering" required of my organs.

 

[Wood]

Sorry for necroposting, but I was just listening to a Ceramic Materials Workshop lecture on this issue and wanted to bring up one specific point here:

Manganism/manganese poisoning is caused by manganese fumes. Manganese carbonate (the chemical form used in pottery) isn't be water soluble, so you can absorb it through your skin. Shouldn't be an issue unless you're straight up injecting it into your veins

 

[Maiden69]

However, the person at the store informed me it should not be used for food contact due to high levels of manganese in the clay body.

I have seen a few potters on Facebook auctions put this disclaimer on almost all the pots. Not that this is a new thread but worth noting

 

[mwar15]

@NaoTK what are your thoughts?

 

[NaoTK]

If you ever visit Central Oregon and have a lot of time, visit the Painted Hills. You must have a lot of time if you are in Central Oregon. This is a heavily contrast-ed image but you can see black streaks where plants that bio-accumulate manganese used to live. The information placard said which plant but I now forget.

Anyways, the amount of manganese we are talking about in a pot is miniscule for a tree (or a human).




On a Central Oregon tangent, did you know dawn redwood is the state fossil of Oregon and dawn redwoods were all over Oregon millions of years ago? If you go to Fossil, Oregon you can dig dawn redwood fossils for free. This is one that I personally dug: