What is Chalk Made Out of?

Calk that kids use in drawing on sidewalks or driveways is made from a soft white porous form of limestone that is composed of calcite. The pastel chalks the kids use are made from calcium sulfate were as the chalk used in classrooms are made from calcium carbonate also known as CaCo3. Other minerals found in chalk could be silica, quartz and feldspar and you can visit this trusted site