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.
Quick Answer. Natural chalk is a common form of calcium carbonate. Unlike other, chemically similar minerals, chalk deposits are laid down by living organisms known as coccolithophores. These microscopic animals thrive in the warm, shallow seas that proliferated in the Cretaceous Period, which derives its name from the Latin word for chalk.