Natural cement, the predominant hydraulic binder of the 19^th century, has re-emerged in the 21^st century as a restoration material. Engineers, architects, conservators, and owners must be able to rely upon modern natural cements to meet the same performance criteria as historic cement materials. In addition to the performance criteria, natural cement must provide the working characteristics demanded by contemporary tradespeople and the aesthetic results expected in high-quality historic restoration work. Historic standards for natural cement are reviewed and criteria used in developing the recently reinstated ASTM C 10 Standard Specification for Natural Cement are discussed. Recent research into the effectiveness of set and flow modifying admixtures with natural cement is presented, as well as an overview of producing color matches for natural cement mortars and stuccos.