Lime has been used in construction for thousands of years in mortars, paints, antimicrobial coatings, adhesives, and plaster and stucco. Lime is the sixth most mined material in the world with uses in nearly every industry from steel to paper production to water treatment. In its purest high-calcium forms, lime is derived from the earth out of shell and stone and carefully fired to drive off CO2 producing an oxide that when hydrated produces a paste (lime putty) with multiple cementitious uses. Mixed with sand it produces mortars and plasters. Lime is used as a clay stabilizer both in the ground and in earthen plasters. Thinned to the consistency of milk, limewash is a durable and antimicrobial finish for both interior and exterior use on masonry and wood, as well as on metal to stop rust. Limewash reflects sunlight, helping to keep whitewashed buildings cooler. Lime is reacted with proteins and oils in the production of a variety of traditional finishes such as casein paints. Lime is also now being used as a bonding agent in conservation of damaged plasters and stuccoes. Manipulation of the transient bicarbonate phase has also been used to reintroduce lime to the matrix of weakened stone and plaster that has been deteriorated by acid rain attack.