These flours are finely ground (intentionally or as a waste product) powders that expose a lot of surface so their trace minerals can slowly be broken down and the nutrients absorbed by plants. Some rock dusts are better than others, some have what your soil needs and some don't, so do your research.

Below is an interesting website that may answer at least some of your questions.

Sue

Why would you think that I am not already aware of that literature? I specifically asked for personal experiences, not literature references.

I hate people who jump on flimsy opportunities to pontificate.

Lloyd

P.S. I am going to read the article on my next set of nights, thx Sue.

Curt~ :-O

If you present a question on a public forum that is here for us to all talk and learn about differnt things and don't care for the ansers to bad for you see its easy for anybody to be rude

Thank you for being the only one to speak on topic. I note Azomite is mostly calcium aluminosilicate.

Here is a retail source for Glacial Rock Dust

I would like to compare (or better, yet, see a comparison of) seedlings grown in pots with and without rock dust, but, in both cases, the plants would also be fertilized with a complete chemical fertilizer. Note that the following excerpt from aforementioned literature is inadequate in that other fertilizer was not added (sort of like the bias in a Miracle Gro commercial):

POT TEST: A pot test will give you immediate, practical proof of what the product will do in the soil. It is a good idea to add the gravel dust to clay pots and plant radishes or other fast growing plants and observe their progress. As John Hamaker writes: "Doing a pot test is the most convincing argument I know of. Anybody can do it. There are testing laboratory grinders everywhere. There is no lag time. In 6 hours you can get a microorganism population explosion. Taking some 6" clay pots, I filled them with a 50-50 mixture of earth and peat and 3 heaped tablespoons of dust. The results were astonishing!

Curt :-)