Despite of the abundance of fibrous, 2:1 and 1:1 clays in arid and semi-arid regions soils of Iran, their influence on hydraulic and mechanical properties remains somehow unknown. A simple and accurate approach to study the effects of specific clay mineral on soil properties and behavior is by preparing sand-clay mixtures. This study was conducted to investigate the effect of four types of Ca-saturated clay mineralsin three rates (15, 30 and 45%) on water characteristic curve, Atterberg limits and consistency indices, swelling-shrinkage behavior, compressibility and shear strength parameters (cohesion, c ; angle of internal friction, ? ) of their sand/quartz-clay mixtures. The water characteristic curve was determined by using sand box, sand-kaolin box and pressure plates. Liquid, plastic and shrinkage limits were measured, respectively, by three-point Casagrande method, thread method and BS-1377. Swelling and shrinkage behavior was studied by coating the mixtures with an Acrylic Resin. Compressibility and shear strength were determined by oedometer and direct shear test (in saturated and 85% plastic limit, 0.85PL), respectively. With an increment in the clay content, water retention increased in all matric suctions. Clay type had significant effect on the water characteristic curve. Palygorskite and phlogopite treatments had no significant difference in terms of scaling parameter ( ? ), but they had smaller ? values than bentonite and kaolinite. Slope in the unsaturated zone followed the decreasing trend of phlogopite kaolinite bentonite palygorskite in the mixtures. Because of fibrous structure, palygorskite had the highest value of saturated water content ( ? s ) and then ? s decreased with the order of bentonite phlogopite kaolinite. The highest residual water content ( ? r ) also belonged to palygorskite due to its high specific surface, then it decreased in the following trend: bentonite kaolinite phlogopite. With increment in the clay content (except 45% of palygorskite), available water content increased with different rates for different clay types. The rate of increase in PAW with clay content in the sand-clay mixtures generally followed this trend: phlogopite bentonite kaolinite palygorskite. The Atterberg limits and consistency indices increased with an increment in the clay content. Palygorskite had the highest effect on the Atterberg limits and consistency indices due to its fibrous structure and very high activity and specific surface. Ca-bentonite with high activity and specific surface had the second place. 3rd place belonged to kaolinite due to low activity and specific surface. Phlogopite-sand mixtures and 15% kaolinite-sand mixture were non-plastic. Peng and Horn (2005) model was fitted very well on the shrinkage curve data with R 2 greater than 0.99 (except 15% of bentonite which showed bi-modal shrinkage curve and 45% of phlogopite which placed on the 1:1 line). Palygorskite had the maximum shrinkage capacity and swelling limit. Then, shrinkage capacity followed the decreasing trend of bentonite phlogopite ? kaolinite. Compression index ( C c ) varied in the order of palygorskite bentonite phlogopite kaolinite. The C c increased by an increment in the clay amount but the rate of increases varied among the clay types. Saturated c was observed with the order of palygorskite bentonite kaolinite phlogopite and at the 0.85PL it followed the decreasing trend of palygorskite bentonite kaolinite. Saturated ? varied in the order of palygorskite kaolinite phlogopite bentonite and at the 0.85PL it followed the order of kaolinite palygorskite bentonite. Palygorskite had the highest cohesion due to its fibrous structure and units as bonding bridges among the coarse particles. Kaolonite had the lowest c due to its coarse particles and weak among links. Bentonite with fine and fexible particles possessed the lowest ? . In general, moisture condition and clay type mainly influenced c , and ? was primarily related to the clay percentage.