1 Apply Aloe vera gel or juice: Aloe vera gel or juice helps get rid of acne scars and makes your facial skin healthier. 2  There are many brands of aloe vera gel or juice available on the market today.
Jupiterimages/Photos.com/Getty Images. Limestones are a class of sedimentary rocks composed of the same mineral, calcite, which is made from calcium carbonate, or CaCO3. Despite this similarity in composition, however, not all limestone rocks are the same. Chalk is actually a special form of limestone that exhibits some differences from other rocks in the same class.
Chalk: A fine-grained, light-colored limestone formed from the calcium carbonate skeletal remains of tiny marine organisms. Tufa: A porous limestone that forms from the precipitation of calcium carbonate, often at a hot spring or along the shoreline of a lake where waters are saturated with calcium carbonate.