Limakerros

Limakerros is a term used to describe a thin crust of calcium carbonate that forms on surfaces exposed to calcareous water. It can occur in natural settings, such as on limestone rocks or cave walls, and in built environments, where lime-based materials are present. The crust is typically white or pale yellow and can range from a few micrometers to several millimeters in thickness.

Formation occurs when water carrying dissolved calcium carbonate interacts with a surface and either degasses carbon dioxide or evaporates, causing CaCO3 to precipitate. Microorganisms can influence the nucleation and growth of the crust, leading to variations in texture. In cave systems, limakerros may develop on drip-water surfaces or on mineral substrates, whereas in architecture it can form as limescale on plaster, bricks, or pipes due to rising damp and evaporation.

In geology and archaeology, limakerros is used to infer historical moisture regimes, mineral provenance, and the chemical conditions of environments. In conservation and building maintenance, it is considered both a record of hydrological history and a potential material issue, since persistent moisture can affect underlying substrates and decorative finishes. Removal or stabilization of limakerros in historic buildings should balance preserving the substrate with preventing moisture-related damage.

Distribution is worldwide in regions with calcareous minerals or lime-based construction, including karst landscapes, limestone-rich climates, and older lime-rendered structures. Related concepts include limescale, calcite, speleothems, efflorescence, and caliche.