Siliceous fossil Animal feed supplement & Soil Conditioner – BioGro Certified Organic. Green Trading Diatomaceous earth powder is made up of tiny fossilized diatoms (plankton) that have accumulated over millennia in freshwater lakes. These pure deposits are mined and ground into a fine powder that is naturally high in silica and other minerals. It is this chalky white powder that we call diatomaceous earth. Ingredients: 100% Food Grade, Fresh Water Sourced, Certified Organic Diatomaceous Earth Powder. Suitable for Human, live stocks and plants.