The use of limestones as facing stones should be avoided in areas where the air is polluted with industrial gases and also in coastal regions where Saltish winds can attack them. In both cases, air is likely to strike the rock chemically and change its surface to spots of reactive compounds. Limestones are widely used in the making of cement.
· Owing to the importance of urinary stones as one of the biominerals in the human body, it is necessary to investigate their chemical composition and mineralogy. In this matter, a mineralogical study using Xray diffraction and scanning electron microscopy indied that urinary stones in Lorestan Province were divided into 5 groups of calcium oxalate, urate, .