TECHNOLOGICAL CHARACTERISTICS

Beyond all desirable aesthetic features of the ornamental stones and covering, the election and use of materials must take account of its technological characteristics. The technological characteristics reflect basically the physical and mechanical behavior of the stones, in the normal conditions of use, allowing the diagnosis of possible aesthetic problems due to the inadequate choice or application of the materials.
For the definition of these and other equally important parameters, it is recommended that all the dimension stone and covering materials be submitted to tests of technological characterization.

The tests have the purpose to mark out the fields of use for these materials, and its behavior towards the requests; they are already demanded by the consumers, and take part in promotional photographic catalogues issued by the great suppliers, as indispensable items.

The evaluation standards and procedures of the results in the technological tests are determined through technical norms. The main sets of norms, not always equivalent in their specification, are defined by the ABNT (Brazilian Association of Technical Norms – Associação Brasileira de Normas Técnicas), ASTM (American Society Testing and Materials), DIN (Deutsch Institut für Normung), AFNOR (Association Française de Normalisation), AENOR (Asociación Española de Normalización), BS (British Standart) etc.

As for the European Community, the European Committee of Norms - CEN, created the technician group “Natural Stone CEN-TC-246”, which has been establishing norms for specification of materials, tests and products. More widely speaking, the specifications signed by ‘CEN-TC-246’ are the ones adapted for ‘ISO-TC-196 Natural Stone’, that regulates the worldwide use of natural rocks.

The six most important tests, appointed as "quality index", are presented as follows.