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This paper presents the results of geological and technological research on clayey and loessoid raw materials from the continental platform of the Black Sea. The loessoid clays undergo an open - cut mining under very good technical-economic conditions and are processed in a neighbouring factory. The clay deposits from the Cobadin plateau belong to the category of silt grains with the particle sizes between 0.01 and 0.03 mm. The physic-ceramic determinations proved that the clays from the Cobadin Plateau have a good shapability as raw materials. The clay preparation and working process includes: maceration in the quarry, preparation of the material by batching and mixing, shaping, compacting, finishing, hardening. The products are dried in the Kowo type natural dryers of the factory and firing takes place in a Hoffman kiln at a temperature of 950-1000°C.

The effective determination of the field and place of application of the products resulting from stone working is a compulsory requirement in the building activity and is solved by laboratory analyses. This article presents details on the determination, by non-destructive method, of the compression strength of the rocks, both "in situ" (in the deposit) and in a laboratory. The originality of the method consists in simplifying the determination process of this parameter, a method that is in agreement with the systems proposed to be applied in the European Community. The method has the advan tage of being applicable in quarries, where knowledge of this parameter leads to a rationalizing of the working and more especially to a selection of the blocks by quality criteria. The method is appli cable to all categories of natural consolidated hard rocks, being a viable alternative for deposits with an inhomogeneous composition as to quality and structure.