Spectroscopic characterization of xx century mural paintings of punta begoña’s galleries under conservation works

•The pigments identified seemed to be unusual for the historical period in which they were used.•Clinochlore silicate painting, under the current mural, was a novel material for the moment.•The atmospheric pollution created a poor conservation state of the paintings.•The analytical analysis have helped to change the vision of a conflict heritage from the Spanish Civil war.