Yeso

Yeso is the Spanish word for plaster and for the mineral gypsum, a soft sulfate mineral composed of calcium sulfate dihydrate (CaSO4·2H2O). As a raw material it is widely extracted from sedimentary deposits and processed by heating (calcination) to produce plaster products such as plaster of Paris, a calcium sulfate hemihydrate that sets when mixed with water by re-forming the dihydrate.

Plaster and gypsum have long been used in construction and the decorative arts. Common uses include interior wall finishes (stucco and plasterboard), ornamental mouldings, casting and mould-making, and as a setting material in dentistry and orthopedics (casts for immobilizing fractures). Gypsum is also used as a soil amendment, in cement manufacture as a set regulator, and in some industrial applications.

Material properties include good fire resistance, acoustic dampening, ease of shaping, and relatively low thermal conductivity. Plaster is brittle and vulnerable to prolonged moisture exposure, which can degrade finished surfaces and promote mold growth unless properly protected.

Health and environmental considerations focus on dust inhalation during cutting or sanding, potential skin irritation from the exothermic setting reaction in thick masses, and the benefits of recycling gypsum waste where facilities exist. In Spanish usage, yeso commonly denotes both the raw mineral and the various plaster products derived from it.