Use of lithoidal granular materials obtained from the combination of the following essential ingredients: - 5 to 50 per cent by weight of a binding system composed by an hydraulic cement or a mixture of hydraulic cements; - 40 to 90 per cent by weight of a contaminated soil with maximum particle size of 4 mm diameter, essentially consisting of carbonaceous minerals, siliceous minerals, siliceous-aluminous minerals or their mixtures; - 0.01 to 10 per cent by weight of a superplasticizer; - 1 to 20 per cent by weight of water. in optional combination with the following additional ingredients: - 0 to 10 per cent by weight of pigments or inorganic or organic colouring substances; - 0 to 20 per cent by weight of silica-fume or other pozzolanic material, both natural and synthetic; - 0 to 10 per cent by weight of calcium sulphate hemihydrate or lime in powder form; - 0 to 40 per cent by weight of fine metallic powder of particle size lower than 2 mm diameter; - 0 to 40 per cent by weight of fine coloured glass of particle size lower than 2 mm diameter; - 0 to 40 per cent by weight of plastic materials with particle size lower than 2 mm diameter; - 0 to 10 per cent by weight of other additives, selected from setting and hardening accelerating additives, setting and hardening retarding additives, viscosifiers, wetting agents, surfactants, impregnating agents, air-entraining agents, hydrophobic agents, water repellents, UV filters, waxes, essences and perfumes, fertilizers and nutrients, herbicides, pesticides and produced by a process including the following steps: - mixing of the essential and optional additional components; - nucleation and growing of the granular material; - optional surface treatments of the grains; - curing and hardening of the grains; - optional post- treatments for the solidification/stabilisation and the remediation of contaminated soils. - 5 to 50 per cent by weight of a binding system composed by an hydraulic cement or a mixture of hydraulic cements; - 40 to 90 per cent by weight of a contaminated soil with maximum particle size of 4 mm diameter, essentially consisting of carbonaceous minerals, siliceous minerals, siliceous-aluminous minerals or their mixtures; - 0.01 to 10 per cent by weight of a superplasticizer; - 1 to 20 per cent by weight of water. - 0 to 10 per cent by weight of pigments or inorganic or organic colouring substances; - 0 to 20 per cent by weight of silica-fume or other pozzolanic material, both natural and synthetic; - 0 to 10 per cent by weight of calcium sulphate hemihydrate or lime in powder form; - 0 to 40 per cent by weight of fine metallic powder of particle size lower than 2 mm diameter; - 0 to 40 per cent by weight of fine coloured glass of particle size lower than 2 mm diameter; - 0 to 40 per cent by weight of plastic materials with particle size lower than 2 mm diameter; - 0 to 10 per cent by weight of other additives, selected from setting and hardening accelerating additives, setting and hardening retarding additives, viscosifiers, wetting agents, surfactants, impregnating agents, air-entraining agents, hydrophobic agents, water repellents, UV filters, waxes, essences and perfumes, fertilizers and nutrients, herbicides, pesticides - mixing of the essential and optional additional components; - nucleation and growing of the granular material; - optional surface treatments of the grains; - curing and hardening of the grains; - optional post- treatments