Zeolite Group
The zeolites are a group of about 30 minerals that are related in structure, habits, and occurrence. The zeolites are hydrous aluminum silicates that contain sodium or calcium, which can replace one another. These minerals are usually found in zeolite deposits, which are of igneous origin. Some of these minerals make beautiful specimens, and are used industrially as water softeners. The water in their structure is in microscopic channels, and can be eliminated without altering the structure by heating the mineral.