The particular sandstones that gave rise to the imposing towers in the territory of Roccamalatina (municipality of Guiglia), 70 mt. and over, are composed of coarse grains (sands), which could also be observed distinctly from a sample even with naked eyes: on rough surfaces, often hidden by white patches of crusty lichens, the grains of light-grey quartz with a glassy appearance stand out, and the milky-white feldspathic ones could be distinguished, while the dark particles of other small rock fragments are rarer.