I'm going a little nutty right now, trying to learn a jargon so I can speak with people who are quite a drive from me and who really don't have the time to spoon feed the ignorant.
I'm looking to buy a few yards of 'crushed gravel sand' to use in a potting mix formulation recommended by Heinz Grotzke in "Biodynamic Greenhouse Management." So far, I've been offered trap dust and 1/4inch (and lower) stuff from a realatively close-by quarry. If I can communicate screen size, I think I can buy what I need. AND, I would assume that it's cool to take basalt instead of granite, eh? Which is to say that I've found a source for basalt trap dust down here. My recollection is that it tests very highly on the Callahan scale (paramagnetics), but I'll have to have it tested again. Thanks _Allan
