Il deposito di bentonite di "S'Abba de sa Pedra" (Chiaramonti, Sardegna nord-orientale).

The paper reports on the investigations carried out at S'Abba de sa Pedra where a bentonite deposit outcrops hosted in the pyroclastic Oligocene-Miocene rocks. The measured reserves were estimated in abou one million of t. Montmorillonite, K-feldspar are the main minerals. Quartz, illite and plagioclase are minor. Chemical composition shows that the materials are mainly of calcium-magnesium tpe. Technological tests point out that they could be used in foundry, for animal litters, in agriculture, as carriers and diluents in pesticide and fertilizer preparation, in the iron-ore pelletizings, for treating waste water and in the production of bleaching, as watrproofing in the waste disposal.