Why Basalt Rock Dust? Basalt deposits are formed by the rapid cooling of magma during volcanic events. Our source is the ancient lava fields of central Oregon. Basalts are mined for a wide variety of applications. A large diversity of minerals is found in the ground dusts of these rocks. Basalt contains high levels of phosphorous as well as potassium along with generous portions of calcium, magnesium, manganese and iron. Another often neglected but essential element found in high levels in basalt rock dust is silica. Silica strengthens cell walls aiding in resistance to stress factors. How to Use Basalt Rock Dust? Basalt Rock Dust is usually applied at 10-20 pounds per 100 ft2 of garden space or 1 cup per cubic foot of potting soil. Advantages Provides an excellent source of macro and micro nutrients Increases moisture holding properties in the soil Enhances the cation exchange capacity Improves soil structure and drainage Mineral Content: Phosphorus (P)........................................................1.56% Potassium (K)...........................................................1.73% Calcium (Ca).............................................................5.58% Magnesium (Mg)....................................................2.16% Sulfur (S).....................................................................0.00% Boron (B)....................................................................0.00% Chlorine (Cl)..............................................................0.00% Manganese (Mn).....................................................0.17% Iron (Fe)......................................................................4.83% Nickel (Ni)..................................................................0.00% Copper (Cu)..............................................................0.00% Zinc (Zn).....................................................................0.01% Molybdenum (Mo).................................................0.00% Silica (Si)...................................................................53.00%