Well my perlite thread was such a success, how could I not make a thread about vermiculite. If you have ever noticed a flaky little hunk of shiny material, looking almost gold in the right light, well you are looking at vermiculite. Like perlite, the pre-processed material is mined. It's a mica substance that has become a kind of clay through weathering. To make the familiar vermiculite product, we heat it so that it greatly expands and bits spall off. Someone thought that the bits looked wormy, and so that is where vermiculite gets its name (compare vermicelli).
Where perlite gives soil a more airy and easier draining character, vermiculite hangs onto water.
watch the vermiculite expand upon heating in this shitty video https://www.youtube.com/watch?v=R2UeCzjnyKQ
Anonymous B joined in and replied with this 4 months ago, 17 hours later[^][v]#1,393,421
I like vermiculite. I'm sorry I missed the perlite discussion, but I much prefer pumice. It does give weight, isn't as conventionally volcanic but porous while adding that weight. Yes it's not puffed glass, so it doesn't float, and isn't as toxic to breathe.
Vermiculite does amazing things for aeration and water holding capacity. The microbial life can always be given more variety. In recycling (or even single use consumption) pumice, vermiculite, turface, natural lava rock or other admixture of graded rock do wonders for potting soil. Granite. Rock dusts themselves become even more beneficial when considering edible crops and herbs. Especially in pots. Sometimes, I prefer leaf mould over shipping vermiculite, but most people go to a store that does the shipping.
Hydroponics based out of vermiculite got taken over by industry stones (manufactured) but it is far better than perlite. (No offense about the perlite, agbiz) At least this isnt as complicated as the biodynamic label. Global sourcing is an interesting thing.