The Neapolitan Yellow Tuff: An outstanding example of heterogeneity

Actually, mechanical features are governed by two concurring factors: a) the mineralogical composition; b) the texture of the rock. In the first case, the predominance of anhydrous phases (analcime + feldspar) over zeolites improves its mechanical strength. By contrast, if the mineralogical composition is constant (similar total wt.% zeolite content), the petrophysical parameters are strictly related to the texture of the rock.