Glauconite is a greenish ferric-iron silicate mineral with micaceous structure. characteristically formed in shallow marine environments. Glauconite has been used as a pigmentation agent for oil paint. contaminants remover in environmental studies and a source of potassium in plant fertilizers. https://www.roneverhart.com/Apple-11-inch-iPad-Pro-Wi-Fi-64GB-Space-Gray-2018-release/