Desiccants and sorbents are specialized, moisture absorbing minerals or chemicals for product protection as well as moisture, oil or spill absorption. A desiccant packet or desiccant dryer removes humidity that could damage products. Silica gel, calcium sulfate, montmorillonite clay, and molecular sieves are common desiccants. Silica gel desiccant is usually packaged in a semi-permeable dessicant bag. Clay desiccant is made from aluminosilicate clay.