I took a drive out to a farm supply store a long ways off today to see if they had anything that looked promising as mineral potting media for succulents and I found a bag of stuff called Cherrystone Grit in the chicken feed department that is made from "sharp insoluble crushed quartzite gravel". It's about 3/16" in size called Size 2 on their website .
Here's the website:
I was wondering if any of you have used this for plants of any kind? The back of the bag says "Also great for also aerating potting mix" and the website says it's even aquarium safe.
A 50 # sack was only $9 so I had to try it, it doesn't get much better than $0.18 a lb!
From their site FAQ just cos it's funny:
"Turkeys raised in the Midwest and Canada have been eating New Ulm Quartzite Cherry Stone Grit since the 1950’s. It’s likely that the bird you were served at Thanksgiving was raised on Cherry Stone Grit!"