The Church of the Company of Jesus in Quito (1605-1765) is one of the most remarkable examples of colonial religious architecture on the World Heritage List. This church has multiple constructive phases and several interventions with no clear record of the entire architectural site, including the historical mortars. A total of 14 samples of coating mortars inside the central nave were taken, with the protocols suggested by the research team and a comparative sample of the architectural group that does not have intervention. The analysis presented in this paper focuses on mineralogical characterization, semi-quantitative analysis by X-ray diffraction and scanning electron microscopy with microanalysis of the samples. The results showed the presence of volcanic aggregate lime and gypsum, used in lining mortars and joint mortars. Mineralogical and textural composition data have allowed the mortar samples to be relatively dated.

The pride of power of the Spanish preachers of religious art is reflected in the church of Santo Domingo built between 1541 and 1688. This work of heritage architecture, one of the first to be built in the colonized city, was affected by multiple earthquakes, interventions, and constructions that do not have a clear record. A total of 13 samples were taken from the lining mortar inside the cloister, central nave, and side chapel, following the nondestructive testing protocols and standards suggested by the research team. The analysis included mineral characterization studies and quantitative analysis by X-ray diffraction and scanning electron microscopy with microanalysis of the samples. The results showed the presence of volcanic aggregates and lime lining and joint mortars, mortars of rustic composition and coarse manufacture. The resolution of the data of mineralogical composition and texture has allowed us to corroborate the historical information described by the chroniclers and to date relatively the studied sites and to establish a hypothesis of constructive stages.