Vi-Olivia Food Grade Diatomaceous Earth comes from an extremely pure, approximately 20-million-year old, fresh water deposit of fossilized Aulacoseira diatoms from the Miocene epoch. There are many different types of diatoms in the waters of the world and they come in many different shapes. Our DE has a tubular type shape that increases surface area and absorption. Fresh water diatoms also produce harder shells and are less mixed than sea water deposits. Our Food Grade Diatomaceous Earth consists of 89-92% amorphous silica (silicon dioxide), trace minerals, less than 0.5% crystalline silica and very low quantities of clay and iron.