Quicklime (calcium oxide) is a white solid having a crystalline structure. Quicklime is highly reactive with water, generating considerable heat in the hydration process. It can be bought at masonry supply stores. CAUTION: HIGHLY CAUSTIC
Hydrated lime (calcium hydroxide) is a dry powder obtained by treating quicklime with sufficient water to satisfy its chemical affinity for water, thereby converting the oxides to hydroxides. It can be bought at garden centers. CAUTION: CAUSTIC
Garden lime is calcium carbonate. It is usually manufactured by grinding marble stone to a fine dust. The dust can be bagged as such or it can be pelletized to make it easier to go through a spreader.
Dolomitic lime is garden lime that contains a small percentage of magnesium carbonate. Most garden lime sold in Georgia is dolomitic lime.