Does it have similar properties to Diatamateous earth which is ground volcanic rock.
White stuff is insoluble and used against grain beetles/mites whereas red is soluble.
The red is highly charged and so when put in soil displaces other elements from the clay in the soil on which they are locked up so making them available to the plant.
I don't know about Diatamateous earth - but see this stuff on Wikipedia: https://en.wikipedia.org/wiki/Diatomaceous_earth
I am not sure about the explanation and prefer to stick to ground I am sure about. I have seen enough to know REMIN does work, with more of an impact on poorer soils than richer soils. For me it is absolutely back to basics - plants have a need for a wide range of minerals and trace elements and REMIN provides them. Aristotle in 350bc said "worms are the intestines of the soil" - another one I love is J von Liebig, see here: https://en.wikipedia.org/wiki/Justus_von_Liebig and his Law of Minimum ie "The yield of the crop is limited by the nutrient in shortest supply". It takes the MINERALS and the LIVING ORGANISMS to make the difference.
As and when you have time, have a listen to my BBC Radio Jersey interview on this page, (press play button, not photo) and hear what my co-interviewee, Jersey's soil guru, Glyn Mitchell and myself have to say: http://www.reminscotland.com/news/