Optical research
Samples of material were studied in thin sections (about 0.03 mm) under the polarization microscope.

Zelená hora hill
Micropetrographic analyses of selected samples of mortars and plasters from the Zelená hora hill complex have discovered follows: The essential sandy component is formed mostly of rounded quartz grains. Another components are feldspars, biotite, muscovite, pyroxen, amphibole, olivine and fragments of scorias. These components occur in micritic carbonate matrix. Rock fragments of metamorphic, igneous and sedimentary rocks were also identified. Description of individual samples is in Tab. 1.

Sample No.:	Extr action place	Colour	Microstr ucture	Composition
1	O1 – mortar	gray	psammitic with micriticcement	quartz, biotite, vitr eous scoria withmullite, scoria with olivine
2	Vz002 IIK – ground floor, stucco from theinitial part of vault near altar, left of mainentr ance	white	basal, micritic	quartz, plagioclase, biotite, muscovite,olivine, pyroxene, amphibole, garnet, calcite?rock fragments: bitite mica-schist,gneiss, marble, scoria with olivine, pyroxene, vitr eousscoria
3	S01 – stucco in the vaultB4	light brown	basal, micritic	quartz, K-feldspar, plagioclase,carbonates, pyroxene, biotite, muscovite, olivine,rockfragments: biotite mica-schist, metaquartzite
4	005 – right of mainentr ance	light brown	basal, micritic	quartz, muscovite, biotite, plagioclase,amphibole, staurolite, calcite?rock fragments: gneiss, mica-schist,scoria with olivine, pyroxene, vitr eous scoria
5	r. 1793 – stucco	white	basal, micritic	quartz, K-feldspar, plagioclase, biotite,muscovite, pyroxene, rock fragments: gneiss, mica-schist,scoria with olivine, vitr eous scoria
6	KII 009 – core	light brown	basal, micritic	quartz, plagioclase, K-feldspar, biotite,muscovite, pyroxene, amphibole, carbonatesrock fragments: tonalite,biotite-sillimanite gneiss, metaquartzite, mica-schist, vitr eous scoria,scoria with pyroxene, olivine and relicts of slack lime
7	S0011 stucco cloister of ledge K1	light brown	basal, micritic	quartz, biotite, muscovite, olivine,pyroxene, amphibole, apatiterock fragments: metaquartzite, marble,biotite mica-schist, scoria with olivine, pyroxene, vitr eousscoria
8	KIII 0011 sample of wall with lettering - r. 1793 Nikolas Tomas	light gray	basal, micritic	quartz, K-feldspar, biotite, muscovite,olivine, pyroxene, rock fragments: gneiss, biotitemica-schist, metaquartzite, marble, scoria with olivine, pyroxene,vitr eous scoria
9	O2 – mortar ofcloister	light brown	psammitic with micriticcement	quartz, plagioclase, K-feldspar, biotite, muscovite, olivine, pyroxene, amphibole, carbonates, garnet, apatite, high temperature baked minerals rock fragments: metaqurtzite, gneiss, silica shells, scoria with olivine, pyroxene, vitreous scoria
10	KI 006	light gray	basal, micritic	quartz, plagioclase, biotite, muscovite,K-feldspar, carbonates, portlandite, pyroxenerock fragments: sillimanite gneiss, metaquartzite

Table 1 - List of selected samples of mortars and plasters of Zelená hora hill complex.

The structure was several times reconstructed and burnt down. It is clear that the exterior of the structure is heterogeneous from a point of view of age and material composition. For historical and conservators needs they were compared parts of plasters of the same epoch. Samples were extracted from walls of cloister and chapel. They were assessed according to binding and filling materials and pores. Results of analyses (Fig. 2) present mostly preponderance of binding material over filling material. Samples can be divided into three basic groups. Within the group A is ratio binding to filling materials 1:1, within the group B 1,5:1 and within the group C 2:1. The porosity of Sample No.: 1 is higher than another ones. This is the sample of mortar from brick joint, which differs also macroscopically. The granulometric study has determined that applied sandy fraction was within fine grained plasters in the range from 0,1 to 0,5 mm and within the medium grained plasters in the range from 0,5 to 1,5 mm. Mineral composition represents Fig. 2.