Movie of "Magical Sand" playing water

Even if it floats in water or it sinks, it makes a lump with sand without doing anything with water, but it is a movie of "magic sand" which becomes smooth again when taken out from water.

Details are as follows.Magic Sand

It is said to be sand made by covering ordinary sand grains with fine silica particles and further exposing it to the vapor of silicon compounds. As a result, it is said that hydrophobicity will be demonstrated.

Originally it was sand to adsorb oil and sink deep into the ocean when oil leaked from a tanker or the like, but it is costly to manufacture and it is not used much.