Representative samples of three Turkish bentonites were investigated with the aim of producing moisture adsorbents, so-called desiccants, of commercial grade 1) Ca-bentonite from Lalapasa-Edirne region (LLP), 2) Na/Ca-bentonite from Cankiri region (CNK). and 3) Na-bentonite from Resadiye-Tokat region (RSD). The samples were composed of smectite and small amounts of quartz. feldspar. calcite and opal-CT and minor amounts of zeolite and dolomite The clay mineral contents of the raw samples were estimated at 75-80% for LLP, 50-55% for CNK and 75-80% for RSD.