Granule/gravel

Sand is loose grains of minerals or rocks, larger than silt but smaller than gravel. Soil contains mineral (often in the form of small sand granules) and organic matter. 

Primary particles. Certain materials widely used as catalysts or supports consist of spheroids of about 10 nm (100 A) in diameter loosely cemented into granules or pellets. The texture of these resembles that of a cemented, loose gravel bed. The 10 nm (100 A) particles may be called primary particles. 

Granules or gravel Sand (very coarse) Sand (coarse) Sand (medium) Sand (fine)... 

Granule Sometimes used to describe particles having sizes greater than about 2000 /an, depending on the classification system used. Also called gravel. 

Both use bitumen (asphalt or tar) for waterproofing the system sand organic fibers in rags, cloth or cellulosic felt saturated with bitumen for reinforcing. Mineral materials such as granules and gravel are applied on surfaces to protect bitumens from ultraviolet (UV) radiation. 

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