The Calcite Crystallinity and the Age of Limestone Brick Mortars of Medieval Objects of the North of the Byzantine Oecumene

The paper describes the process of recrystallization of portlandite of limestone mortar in calcite. The degree of crystallinity of calcite in limestone mortar of some medieval objects of the north of the Byzantine oecumene is shown through the example of Abkhazia and calcite in natural limestone and marble. The work provides a comparative analysis of the calcite crystallinity and the estimated age of the building objects according to historical and architectural data. It is proven that the higher the calcite crystallinity is the elder the lime mortar and, accordingly, the architectural object is.