Unified European Norms for Natural Stone
The following standards may be considered unified European norms within the terms of article 4, paragraph 2, point a) of directive 89/106/CEE:

EN 1341:2001 Natural stone slabs for external paving - requisites and testing methods
EN 1342:2001 Natural stone blocks for external paving - Requisites and testing methods;
EN 1343:2001 Natural stone kerbs for external paving - Requisites and testing methods.

The unified norms (art. 8) are the specific techniques (more simply they outline the controls to be carried out on every finished product, how they should be carried out and how often) adopted by the CEN.
Following technical specs leads to determining the suitability of the products tested and makes that suitability visible by means of the CE quality mark, whose logo confirms that the product complies with European specifications.
Among the various control systems set out by the directive, the most economical for the manufacturer is to refer to a laboratory for the physical, mechanical and usage tests in order in the first placed to characterise the product and after that according to the calendar specified in the norm.
The manufacturer should also (even on a daily basis) check his production with simple tests, the results of which must always be registered and made available for any controls.