Abstract The Verbano–Cusio–Ossola quarrying district (Piedmont, northern Italy) produces many different ornamental stones (granites, gneisses, marbles); two important categories are represented by Serizzo and Beola gneisses. The Serizzo , a group of foliated orthogneisses, is the most important and extensively exploited ornamental stone, largely used to produce columns since the end of fifteenth century and used for many parts of the Duomo di Milano. Beola is the name of a group of heterogeneous orthogneisses with mylonitic foliation and strong mineralogical lineation, easy to split into thin slabs with hammer and chisel, occurring in the middle Ossola Valley. The quarries of Beola are probably the oldest of the Ossola Valley (since the Roman period), and the Beola trade probably started at the end of the thirteenth century. In general, Beola and Serizzo gneisses have been used for ornamental purposes and for the construction of churches, palaces and monuments, widely documented in many towns and villages of the Ossola Valley and in northern Italy. This contribution reviews the history and distinctiveness of these materials, their importance in local and national culture, and their present international diffusion. Both stones are recommended as Global Heritage Stone Resources within a Global Heritage Stone Province.

Abstract Residual sludge from dimension-stone working plants, both from gangue saws with abrasive shot and frame saws, is classified as waste and presents a number of problems for the stone industry. These problems include a fine size distribution, heavy metals and total petroleum hydrocarbon (TPH) content, all of which impede recovery and reuse. Residual sludge, management of which is administered in accordance with the Italian Legislative Decree 152/06, can be used in waste form for environmental restoration or for cement plants. However, it is also possible that sludge applications could go beyond these limited uses with incorporation of systematic treatment for the production of secondary raw materials (SRM), for example, filler, or for ‘new products’, for example, artificial loam. Such new products or SRM have to be certified not only on the basis of their technical and physical characteristics but also by means of appropriate chemical analyses to guarantee that the products are not contaminated. This paper outlines the results from laboratory and in situ characterization of residual sludge. In particular, three potential applications of sludge either by itself or mixed with other materials were evaluated: landfill waterproofing material, filler material for civil works and artificial soil for land rehabilitation.