Why is desert sand softer than sea and river sand?

The magnitude of velocity of air in deserts is too high, ranging from 5 meters/sec to 50 meters/sec [1], whereas stream velocity of rivers 0.4 m/s to 2 m/s [2]. read more

Whereas river and sea sand is used all over the world for construction purpose since the particles have the proper size to bond with cement. The fineness of desert sand makes it softer in comparison to river sand and thus not useful for construction. read more

Sea and desert sands seldom satisfy the requirements of traditional specifications for use as a construction material, especially in their untreated state. Desert sand grains are finer and smoother so their surface chemistry would not be able to offer sufficient number of multidirectional chemical linkages. read more

When sand is just damp and contains a mix of air and water the surface tension of the water droplets between the grains comes into play and this effectivley sticks the grains of sand together and makes it much more solid. read more