This is a high metamorphic degree orthogneiss with a gneiss layering characterised by medium-grained quartz and feldspar crystals that give and eye-gneiss look to the cut perpendicular to the foliation plane.
The texture is characterised by thin and repeated films of black mica alternated by light lenticular levels of homogeneous medium-granined quartz and feldspar crystals.
In the cut parallel to the foliation, the stone presents a structure with interdigitated stones of light and dark minerals, with a preponderance of the black micas (basal plane of the biotite), which make the stone darker.