It is “metabasalt.” Basalt rock that was heated and pressured for millions of years.
Has calcium, magnesium, iron. 2,4,4%
The large particles will also help break up clay.
For garden, 5-10lbs per 100 sqft
for trees, 1-2lbs per inch of trunk
I personally do not use because it is expensive, heavy, and i do not till my clay, but rather tarp and no till transplant on top of compost.
