1. Use of stone in construction

The division of stone mining basins in France is generally independent of geographical or geological units. Thus, the same region or department can be made up of several geological units, and conversely, the same stratum or stone deposit can be found in several communes, departments or regions.

Stones may thus have similar or comparable petrographic characteristics, but different names, even if they come from the same deposit or from geologically very similar deposits. Conversely, stones from the same quarry, but not from the same bed or geological unit, may have very different properties.

The notion of deposit is particularly important, and it is sometimes easier to reason in terms of stone type, grouped under a general name corresponding to the deposit or reference layer, rather...