Question

what do you mean by the term effloresces

Answer 1

Effloresence means the crystalline deposit over the surface of rock. Normally through capillary action the water content of the mineral comes to the surface and evaporate. Ex., Gypsum
Certain liquids gets evaporated and it forms white crystalline deposit over the surface. For ex., Ammonium chloride solution on evaporation at room temperature forms white crystalline NH₄Cl crystal at the surface.