The physical breakdown of stone caused by the growth, hydration, or thermal behavior of salts within pores, fissures, and surface layers.
Haloclasty, also called salt weathering, is the physical deterioration of rock or stone caused by salts acting within pores, fissures, and near-surface layers. As saline moisture enters the stone and water evaporates, salts may crystallize and generate pressure against the pore walls.
Repeated cycles of crystallization, hydration, and environmental change can produce granular disintegration, scaling, flaking, and loss of carved detail. Haloclasty is therefore an important conservation concern for outdoor stone sculpture, architectural carving, and monuments exposed to marine salts, de-icing salts, rising damp, or contaminated water.
Etymology
Modern scientific compound from halo-, referring to salt, + -clasty, meaning breaking or fracturing.
Sculptor Notes
For the sculptor, salt damage can be especially destructive because it attacks edges, tool marks, polish, and fine detail first. Conservation requires identifying the source of salts and moisture rather than merely treating the visible surface loss.
References
https://onlinelibrary.wiley.com/doi/10.1002/9781394312436.ch2; https://www.pierres-info.fr/glossaire/index.html