Black Pearl Granite

Macroscopic description

Mesocratic natural stone, with gray tonality, containing dispersed black crystals of centimetric dimension and of holocrystalline and massive form. It presents granular, phaneritic texture, from fine to coarse grain. The constituent minerals generally present grains with an anhedral to subhedral shape and some with a prismatic tendency, without lineations, cracks, pores or cavities. The rock does not present any type of orientation, foliation, shale or apparent tectonic deformation.

Microscopic Description

CHARACTERISTICS

It is a basic natural stone of intrusive igneous (plutonic) origin, composed mainly of non-equidimensional grains of plagioclase and pyroxene.

TEXTURE

The natural stone has a holocrystalline, phaneritic, non-equigranular texture, of medium to coarse grain, with a hipidiomorphic tendency.

MAIN MINERALS

Ortopyroxenes (5%), occurring with an antheric or prismatic habit. Clinopyroxenes (3%), occurring with anhedral to subferric habit, sometimes presenting alteration aureoles. Plagioclase (90%) in crystals with a subhedral or prismatic subidiomorphic habit, with hydrolysis phenomena, which promote its alteration.

MINERAL MINERALS AND ACCESSORIES

Biotite (2%) and opaque (<1%) disseminated by the mass of the sample.

SECONDARY MINERALS

Clay minerals (2%) occurring in the nucleus of altered plagioclase and disseminated iron oxides.

Technical Characteristics