Please note that our wall facing bricks „Brickstones“ is a natural product that discolors in its own way when used outdoors.
Cause of discoloration
Discoloration of natural stones can be caused by
- the penetration of discoloring substancesfrom the surface
- the discoloration of substances from the stone
- the penetration of discoloring substances from the substrate discolorations caused by the
Transformation of substances in the stone are, for example:
- Pyrite deposits in granite, marble (Bianco Carrara) slate gneiss (Serizzo)
- Biotite occurrences in granites (Bianco Sardo) and gneisses
- Garnet occurrence in garulites (Kashmir white)
- which can be converted to iron hydroxide (limonitization process) by environmental influences and lead to rusting out.
This transformation cannot be prevented, as it is a natural weathering process of the stone. Due to evaporation of excess water of the mortar in the substrate, e.g. substances can pass through the capillaries of the natural stone to the surface and cause discoloration there. Such substances can be partly organic (cigarette butts, tar residues, cola) and partly inorganic (lime from the materials for concrete and glue). The latter are called efflorescence.