History:
Synonyms and other names: Slaked Lime (Slaking-the process of combining (lime) chemically with water or moist air), Hydrated Lime.

It is supposed that calcium hydroxide has naturally occured forever, and never truly been created, or experimentally discovered. Ever since early man lime has existed, but the properties were harnessed primarily from the early Norman Period in England. Both the early Egyptians and Normans used lime in combination with other native elements such as sand to produce concrete and mortar. Cultures throughout history adapted their techniques with lime and concrete, producing such amazing results as Roman Concrete. However, calcium hydroxide is actually produced by hydrating regular calcium oxide, a white crystal. ( CaO (s) + H2O (l) -->(heated) Ca(OH)2 (aq) ).

For more information on the history of lime and mortar visit Carlos Sicilia's webpage, "The History of Lime and Mortar".