Magnesium oxide is produced by the calcination of magnesium carbonate or magnesium hydroxide. These are cocrystallizations of potassium sulfate and sulfates of magnesium calcium and sodium. Other important nutrients include phosphorus, sulfur, calcium, potassium, magnesium and manganese. Sodium, potassium, chloride, calcium, magnesium, and phosphate are examples of electrolytes. Varying amounts of potassium, sodium, phosphorus, calcium, magnesium, iron, and zinc were present. Common macronutrients analyzed include compounds of nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur. Deficiencies of boron, zinc, calcium, magnesium, and sulphur are high. Problems with blood levels of potassium, magnesium and calcium may also contribute. Adequate levels of phosphorus, potassium, calcium, magnesium, and micronutrients are also necessary for good yields. Several methods are used to separate potassium salts from sodium and magnesium compounds. The transformation of smectite to illite produces silica, sodium, calcium, magnesium, iron and water. It is composed of clay colored by iron oxide, magnesium, aluminum silicate, or potassium. Like konbu, wakame is rich in minerals like iodine, magnesium and calcium. Yerba mate also contains elements such as potassium, magnesium, and manganese. These include such metals as zinc, magnesium, and cadmium.