This grit has all the qualities and benefits of the national grey grit plus an abundance of iron oxide.Calcite Granite Grit Salt Niacin Dicalcium Phosphorus Vitamin A Supplement Vitamin E Supplement Vitamin D3 Supplement Vitamin B12 Supplement Potassium Sulfate Magnesium Sulfate Iron Oxide Biotin Monocalcium Phosphate Anise Etc.