Limestone ground to a fine white powder, made by burning raw stone and then crushing and sifting the result. Masons use it in mortar and whitewash; tanners add it to hides to reduce grain; farmers spread it on fields to reduce soil acidity. The powder is caustic and will burn skin if wet, so it is kept in a sealed pot and handled with caution.
Limestone, powdered
White caustic powder; mortar, whitewash, soil acidity; kept sealed, handled cautiously.