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New page: Chalk is a white, Sedimentary rock, composed of calcite. When chalk is formed naturally on a hill, it is called downland. Nowadays, chalk has been replaced by other substances. For exampl...
Chalk is a white, Sedimentary rock, composed of calcite. When chalk is formed naturally on a hill, it is called downland.
Nowadays, chalk has been replaced by other substances. For example, the "chalk" that is used in blackboard writing or in sidewalk chalk is actually gypsum.
Nowadays, chalk has been replaced by other substances. For example, the "chalk" that is used in blackboard writing or in sidewalk chalk is actually gypsum.