Illustration of the molecular structure of a zeolite framework. Zeolites are hydrated aluminosilicate minerals and have a micro-porous structure. They have the general formula (MAlO2)(SiO2)x(H2O)y where M is usually hydrogen (H+) and sodium (Na+). Zeolites can have different framework structures; this the common Linde Type A form of Zeolite. Zeolite materials are used in water purification, soil remediation and waste treatment systems, and are being investigated for use in the capture and storage of greenhouse gases, including CO2.