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.
Marble's crystals are usually larger than limestone's crystals. Like limestone, marble is usually made of calcite, so it usually fizzes gently when you put a drop of white vinegar on it. Chert: Pieces of chalky white or dark chert are sometimes mixed with limestone gravel.