Lime is calcium carbonate, the main source of which is limestone.
Lime mortar is produced in a process which basically involves, burning the limestone, then adding water to produce a base material to which various aggregates or additives are introduced depending on the end use of the material which can be anything from painting to building. The principal of lime mortar is that by a process of carbonization, the material reverts to calcium carbonate, which is stable, and depending on what has been added, solid. Hydrated Lime - is produced when just enough water is added to quicklime to slake it, most lime is supplied bagged and powdered, in this form. This set is caused by clay substances present within the original lime source, in effect a naturally occurring additive. Lime wash - in effect a very thin lime putty, used as a paint or protective coating, can contain a binder such as linseed oil or tallow.