Volcanite: A blend contains four different volcanic, paramagnetic crushed rocks including zeolite. The zeolite is no longer paramagnetic but it has a very high cation exchange capacity, and since we are low in iron I also added glauconite – a sedimentary mineral rich sandstone commonly called greensand. A blend of several rock materials from the Garden-Ville Company in San Antonio including basalt, lava sand, zeolite, granite, and Texas greensand. This blend works better than any of the ingredients used alone. It’s very economic because only small applications are needed to increase production. Overuse of this material can actually reduce production. Recommended rates are 1000-2000 pounds per acre, or 50 pounds per 1,000 square feet.