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.Continue Reading
Natural chalk has been used in its raw form by artists for as long as humans have been etching cave walls. Sometimes impurities are found in the chalk bed, which lend various colors to the chalk. Commercial chalk is usually derived from natural chalk, but with various additives to enrich the color and give it greater strength.
Commercial chalk, of the kind most often used in classrooms, is made from ground chalk powder that has been hydrated and mixed with clay for a firmer consistency. Dyes can be added to give the chalk a desired color. Black chalk, for example, usually contains carbon. Red chalk is often made with ferric oxide, which is a mineral form of iron and oxygen. Some "dustless" varieties of chalk are sold as sticks that have been dipped in a vat of artificial shellac that binds and seals the stick's surface and keeps the chalk from shedding.Learn more about Chemistry
According to Discovering Fossils, chalk occurs naturally in nature as calcium carbonate, a form of limestone. Limestone is formed from the decomposition and sedimentation of Coccolithophores skeletons, a type of plankton.Full Answer >
Differences between calcium carbonate and calcium citrate supplements include absorption, calcium content and pill size. Citral is a popular calcium citrate brand, while Caltrate and Tums are popular calcium carbonate brands.Full Answer >
Calcium carbonate has different uses including as a dietary supplement, an antacid and chalk. Other uses include as limestone and marble in the construction and manufacturing industries. Calcium carbonate has the chemical formula CaCO3.Full Answer >
Depending upon the brand name, some of the active ingredients found in antacids include magnesium carbonate, aluminum hydroxide, calcium carbonate and sodium bicarbonate. These substances are bases, and can help to neutralize the stomach acidity that causes discomfort by increasing the pH level. Over-the-counter brand-name medications, such as Maalox, Tums, Rolaids, Brioschi, Pepto-Bismol, Alka-Seltzer and Mylanta, are all antacids.Full Answer >