Search for a rock quarry that is close to you. They should all have rock dust for sale.

I recall seeing a number of quarries on the outside of Nashville, particularly on the Southern end. I think one of them is a Rogers quarry. I don't know how many of the quarries actually sell rock dust; quite a few that I've seen don't, but Rogers might be worth a try. They are a very big enterprise, and might know who to go to if they don't have it.
Renais

Here is a link that might be useful: Rogers

Why do you think you need to "re mineralize" your soil?
What are the indications? What does a good, reliable soil test say? What minerals do you think you need? Could the apparent need for those minerals be the result of a lack of organic matter in the soil?

Thank you, Renais. I appreciate your suggestion. I'll try that. And Kimmsr, please do some research on 'remineralizing the soil' on goggle. "Goggle" the words 'rock dust' and 'remineralization'. There is a whole new science sweeping the horizon concerning what makes nutrient rich vegetables. I agree with you that the soil needs organic matter; but when you add the rock dust you enhanse the compost ability to feed the microbes that inhabit the soil and make truly fertile. Please do some research on this. I think you'll be amazed at what some very good soil scientist are finding. Best wishes.

You might look into Azomite dust.

Fifth Season Gardening
Fifth Season Gardening Company 45 Banks Ave
Asheville, NC
(828) 253-4112
Toll free: (877) 653-4112

I have azomite and apply it to my compost. But rock dust seems to be different according to all the research I have done on it. I'm just puzzled by the response I get at every quarry I've called because they do not seem to have a 'rock dust'. The stuff they have is much more corse. It must be 220 mesh in order for the microbes to consume it and they don't crush it that fine. I'd be happy if only I could find a store that sells it.

Rock dust is not a common product of the quarries I've visited. Around here, folks who are doing the kind of remineralization you are talking about use crusher fines. These fines are much coarser than what you are looking for; they are also quite a bit cheaper. If you can find a place that has rocks with the minerals you want in it, they likely will have crusher fines in my experience. I know of only one place within about 250 miles of me that has the dust. For pricing comparisons: crusher fines cost $15-25/ton; rock dust, at the one place that had it, costs $280/ton. If you need the minerals, you can put on the layer of crusher fines and let them age in the soil. The soil chemistry will very slowly break them down. The acids in decaying organic matter can help with the decomposition. For short term remediation, you might find that Ironite has what you need. Around here a 50 pound bag costs about $12 on sale. Sams Club carries it sometimes. Good luck with your quest.
Renais

Also perhaps a search for crushed lava rock or lava sand. May find that in your area.

The stuff produces miracles only if your soil is deficient.
As was asked previously, have you had a professional soil test done? If not, please do so.

Further, using rock dust isn't new. If it's "sweeping the world," it's simply a new surge.

I have done research into "remineralizing" soils and most of what I have seen is nonsense. Most of the justification for it comes from what is called "conventional" gardening, the folks that promote the use oif synthetic materials.
If a soil lacks adequate amounts of organic matter a good reliable soil test may well indicate a lack of many necessary nutrients, including minerals. Plunking down some rock dust, and not addressing the lack of organic matter will not help because the Soil Food Web will not be there to convert that dust into usable plant nutrients.
In over 40 years here I have added nothing to the soil except organic matter. yard waste and compost, and the soil tests tell me that the soil has ample nutrients plants need to grow strong and healthy.

Rock dust is the same as the weathering of sand. Sand is continually weathering in your soil the same way lichens eat the large rocks.
When I first read about it they were pulverizing sand rather than calling it rock dust. Sedimentary rocks and sand are they same thing aren't they?

"Sedimentary rocks and sand are they same thing aren't they?"

Hardly. Sand is quartz with little or no nutrients. Sedimentary rocks can have many nutrients like potassium, phosphorus, calcium, magnesium, copper, zinc, boron, mamganese, molibdenum, cesium, stronium, iron, vanadium, and you get the idea.

Just saying that these rocks are unneeded out of hand is a bit quick on the trigger. What about all the micros that are untested for"
Do you wait to be confirmed with a deficency in your body before taking any supplementary vitamins, minerals, and anti-oxidants? I would hope not. There used to be goiters due to iodine deficency. Probably millions today have low iodine with thyroid problems..Get a grip people.

The attached link has sources of rock dust around the country, as well as some comments about soil remineralizing for those interested. I've never considered that my soil needed any work, and still don't. However, I attended a science and growing conference a number of years ago sponsored by a university in Arizona, and the topic came up multiple times. For the commercial growers and scientists there, remineralizing was a very important topic because it impacted brix readings for tomatoes, and certain other products. Hydroponic growers routinely add the appropriate minerals, but it can sometimes be overlooked for in-ground planting. The growers were most concerned about brix readings for produce bound for, or produced in, the international market where a higher brix reading is required for consumer acceptance. I remember, for instance, that Japanese tomatoes are required to have a higher brix than almost all tomatoes sold on the US market. Another reason some growers advocated adding the rock dusts was that they analyze their in-ground produced produce for multiple trace minerals (for specialty health food markets, for instance), and found that rock dusts and other additives made a difference that was quantifiable. Most consumers will probably not care about these issues, but there are folks who look at the total nutrient load in their food. Rodale has also done some good work looking at making food mineral rich, and not just pretty, long-lasting and easily shippable. I believe they hoped to achieve their goals with both the import of organic matter with certain trace elements, and rock additions (not necessarily as dusts, however).
Renais
Renais

Here is a link that might be useful: Sources

Interesting discussion.
But I'm confused.

Some questions:
Isn't all soil basically rock dust with some other stuff, like OM mixed in?

If your area is deficient in one or more minerals, and you buy rock dust from a local quarry, won't you be putting on the same mix, and therefore same deficiencies as you already have?

Isn't Azomite considered beneficial because it is taken from a unique area that has high levels of some minerals that are normally lower in most US soils?

Therefore, if something is "rock dust" why would it be worth adding unless it has been tested and your soil has been tested and the rock dust you're buying definitely has the minerals that your soil lacks?

If someone could clear up this confusion, I'm all ears. (or eyes . . .)

I have studied and experimented quite a bit with remineralization. As stated above, it gets results in severely leached soils. For soils with silt and/or clay it is, IMO, not worth the expense and effort. In those soils local OM additions is a better return.

Pat, I can see where sandy soils and/or soils with high rainfall can have minerals never present or leached into the subsoil or even out to sea. These are prime candidates for minerals and organic matter.

Other and heavier soils are lesser candidates, but....unless nothing has been removed from them, it seems possible/likely that a moderate dressing is wise.

"Isn't all soil basically rock dust". Yes. A good healthy soil also has adequate amounts of organic matter in the mix. Adding "rock dusts" to soils without adequate amounts of organic matter will result in little benefit since the Soil Food Web that is needed to convert those minerals into something plants can use is missing.

The worst soil for raising typical crops in the typical way that I have experience with is florida sand. It is true IME that adding rock powders without some form of OM in that soil/climate has no effect, or at least no effect in a time scale of a few years. I found that a much better strategy is to switch to permaculture, and use of rock powders can have a minor place in permaculture in some cases.

Wayne, you would know about prime soil better than me, so I defer to your experience..

In the reading I have done a good balanced source for rock dust is of glacial origin due to the mix and the fine powder. Also volcanic origin. I mean isn't it generally accepted that volcanic soil is a rich growing medium? I personally use rock dust and plenty of OM. Have for years and very happy with the results.

+1 greenleaf.

If the extraction, processing, and movement of rock dusts uses non renewable resources (most do) then rock dusts to a real organic grower are not acceptable. Current methods of extracting, processing, and moving these rock dusts around are not sustainable, not mako9ng ecological sense., aside form not being needed.

Kimm, Does this apply only to gardens?

Do you use gasoline? electricity?

I believe you are a tad fanatical. To each his own though.

Kimm, that is completely silly and illogical. If you apply that concept evenly then organic growers cannot use "non-renewable" resources anywhere in the chain, which means no motor-powered equipment, and no imported fertilizers or compost, or packaging materials, or greenhouse plastic, metals of all kinds, etc.

IOW, no operation could function, including the average backyard gardener.

I agree with Kimmsr, this is not needed in most cases (have you done a test suggesting it is, or what sort of malnutrition are you seeing?), and yes the 'creation' of storebought rock dust including mining, trucking and packaging is totally not sustainable compared to simply composting, vermicomposting and even teas, all easy to do at home and all more beneficial showing clear obvious results immediately, unlike rock dust.

Seems like another overpriced gimmick for well meaning gardeners to me.

I've been noticing overpriced 'glacial rock dust' for the last few years and even bought a couple buckets 'in case I was missing something' and after research realized the only benefit I'd receive was moderation of the pH that'd been cheaper to simply use dolomite.
The volcanic products I am still open to trying.

"Kimm, that is completely silly and illogical"
Only to those that are not really organic growers and are not concerned about the environment we live in. And no, Wayne, it does not apply only to gardens. The concept applies to your whole life. We try to not be consumers of waste, limiting what we use as much as possible and recycling, reusing, repurposing as much as possible, and purchasing needed supplies from sources as close to home as possible.
That is, and has been, at the root of organic gardening/farming for many years.

Not finding anything at all in discovering the composition of rocks of any kind. Rock dust supposedly contains 72 different minerals but there is no science site from Universities that say anything about it.
The only familiar elements that have been mentioned anywhere is potassium and calcium.

Has anyone had any luck in finding a rock composition site that discusses the minerals used by plants? Other than the advertisements, I mean. :

Soil = weathered rock + OM + SFW = rock dust + OM + SFW

No?
Can anyone explain to me why this is not true?

Other than rock dust that was recently glacial or volcanic, which may mean that it has some things that have been washed out of soil (which was also glacial or volcanic, but a very long time ago), why in the world would you buy such a thing? (I'm beginning to feel like Rosanne Rosannadanna)

Why the heck would you want something from a local quarry? (assuming local = same stuff you've already got)

Rosanne

elisa, Not all soils were created and treated the same by mankind and nature. I have read tests of minerals like calcium, magnesium, phosphorus, and potassium on sites from a hundred years ago. There was descreptancy between areas on the total volume in the topsoil. Eastern areas had generally leached the calcium down and any other leachable minerals. Sand never had much in the way of minerals....except insoluble silicon.

So, one size does not fit all. We have tended to mine the minerals by taking crops off the land and sending them to the cities...which do not send them back. Also there are many micro elements like Yttrium, cobalt, chromium, vanadium, stronium, molebdium, copper, and many others that while not being critical to plant life, are to human life.

A good soil synergy will make available nutrients, if they are in the soil to begin with. Not everybody has optimum soil synergy though. I don't want to come up short, but rather supplement at least some as insurance. Do you supplement with vitamin D3? You should. Most people are short even though the sky is full of it above the clouds.

Malcolm Beck wrote about the virtues of volcanic rock dust in this linked excerpt from his book. He used to sell gardening products but is now retired so forget about me trying to sell anything here. This is purely for informational purposes. I bring this to your attention because he has conducted studies.

Here is a link that might be useful: paramagnetism of volcanic rock

I totally get the volcanic rock dust idea (I use Azomite--which, by the way, I picked up when I was driving by the house of the guys who run the company, so zero carbon footprint for getting it to my house from their garage)

It's the local rock quarry idea that had me stumped.
But if the rocks have stuff in them (GOT to get my daily supply of Yrrtium or I feel like a wet rag) that the nearby soil doesn't, because the rocks have not been leached yet, then that makes sense. Right--the rocks haven't been rained through yet.

Thanks, wayne, for the explanation.

Going to the fridge now for some D3 drops.

I have piles of azomite that I'm not using for now because want to check it with a geiger counter first.

Yes, seriously.

Seriously???

Yttrium would set off the geiger counter, no?

Please do report what reading you get.

Has the rocks containing the micro-nutrients we say is gone from most soils, been mapped out?
Is there any valid research that demonstrates which rocks carry the desired minerals?
Do some rocks actually contain all 68-72 elements in one dusting?

The only link provided was by a salesman's book from pre-retirement era.
Sounds suspicious to me. :)

Pat, This copied from the Azomite site...

"No, AZOMITEî is no more radioactive than common dirt. While there is a very slight reading with use of sophisticated instruments, it is primarily associated with the amount of the valuable potassium contained in AZOMITEî. The reading is comparative to the reading for a radish, carrot or Brazil nut and even lower than the typical amount from a glass of milk. For more detailed professional data, please refer to the most recent gross alpha/beta test report prepared by the Life Sciences Division of ALS Environmental Laboratory Group û.

Maple, why don't you conduct your own research then? Also I would look to your nearest organic nursery to get input for what works good in your area.

Yes, Wayne, I have read everything on the site. I'm not saying they are lying, but OTOH they aren't going to say that the product is 10 or 20 or 100 times background, are they?

When we consider that hardwood ash in the northeast typically reads over 250, and it is well-known now that the nuclear testing from the 50's and 60's resulted in trees all over the eastern half of north america to sequester large amounts of heavy isotopes, then one has to consider what other effects that testing has had, such as the possibility of fall-out settling on desert soils.

My research deadended so I was hoping to have help finding something definitive on the subject.
My opinion on micro-nutrients is that trees likely mine everything a plant needs from inorganic sources beneath the ground and store them in their bodies.
Leaf, bark and mulched up wood should provide a fairly well rounded bit of organic nutrients.

i can't find any research on that either. :(

I'm sorry Maple I misspoke. I actually meant to say why not conduct your own experiments such as the ones in the article.

My question is about "Rock Dust" as discussed in this thread.
If the minerals in rock dust do not come from the same old sedimentary rock decay from all around the world, then where does it come from?
I was incorrect about lumping sand in with the generic sedimentary rock decay because sand is more igneous, but why would rock dust from one place be full of 68 minerals and not other places?

Hey Maple I see. Well I am no geologist and others on this forum could probably answer more completely but here is how I understand it. Igneous rock being volcanic is a hardened form of a molten bubbling mixture which has a broad spectrum of minerals having come from a "molten blenderizing" of material deep in the earth. Glacial is a mixture too because as giant ice sheets traveled they crushed rocks underneath them and pushed them along under many tons of pressure and also in effect causing a mixing and powderizing outcome yielding a variety of minerals in its make up. Having said that, even so, I also understand that different sources of either glacial or volcanic rock dust will still vary in their composition somewhat. This is why I suggest getting in touch with local organic growers and nurseries familiar with local soil conditions and the best available rock dust to balance local soils. Remember, as most would probably agree and as you probably already know, OM is the first priority.

Maple,

My understanding is the answer to your question lies in historical precipitation. Fine rock dust was liberally spread around the planet following the last glacial maximum. In wet areas (like the eastern half of north america) most of that deep fertility was leached out (with a lot of help from humans in the past 500 years or so). In very arid regions like the SW of north america, there has been enough rain to wash out the sodium chloride but most other active minerals have remained.

There is apparently evidence of truly epic forests (with staggeringly huge trees) that existed about 5-6000 years ago over most of the temperate latitudes. If what I wrote above is at all true then these were already declining by the time humans had iron cutting tools.

I'm aware of 3 types of rocks and I've never heard of fertile rock dust precipitating on the planet before.
Interesting. :)

Igneous would be quartz or diamonds formed from intense heat and pressure and end up looking like glass.
Sedimentary rock is the basic unaltered sandstone or limestone type material that hasn't been altered much by heat or pressure.
Metamorphic is the rock that could have been either igneous or sedimentary or both, at one time but was altered by intense pressure.

My guess is that rock dust would come from Sedimentary rock because I could not imagine that minerals would be recoverable from the other 2.
If it came from another source it would be important to know that We need to find some actual science out there. :)

The link below lists nutrients in tree leaves.

Here is a link that might be useful: Nutrients in tree leaves

Thanks kimmsr, that's a good article. :)

I notice the balance of the calcium/magnesium is automatically close to what is talked about as ideal:
"Application of leaves at 20 ton/acre would also add on average 656 pounds of calcium, 96 pounds of magnesium, 44 pounds of sulfur, 1.5 pounds of boron, 58 pounds of iron, 22 pounds of manganese, 50 pounds of chloride, 4 pounds of sodium, 0.3 pounds of copper, and 3 pounds of zinc. The actual amounts of nutrients applied can vary considerably as shown by the concen�tration ranges in Table 1."

The superintendent of a rock quarry in SC told me that it is not economical to haul rock more than about 40 miles so there should be some quarries not far away. You probably don't want a quarry over toward Knoxville as that is merely folded sedimentary rock more like limestone. The fines washed from crusher-run granite aggregate are your best bet. They may even be considered waste and free for the digging. The leached quartz sands of the coastal plain are the Carolina soils most in need of other minerals, such as the feldspars abundant in granite. The highly leached sandhills soils are the poorest and most in need.

This post was edited by gonebananas on Sun, Nov 30, 14 at 17:35