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.