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 is a type of limestone that contains mostly shells from marine animals. During the 1700s, limestone was used for lithography which is when pictures are drawn on stones and then copied to other stones. Because limestone contains the remains of dead organisms, it is considered an organic sedimentary rock.