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.
Best Answer: Chalk is formed from lime mud, which accumulates on the sea floor in the right conditions. This is then transformed into rock by geological processes: as more sediment builds up on top, and as the sea floor subsides, the lime mud is subjected to heat and pressure which removes the water and compacts the sediment into rock. If chalk is subject to further heat and pressure it becomes marble.