Calcium carbonate powder (CaCO3) is a naturally occurring white, insoluble powder-like substance that has many uses:

• Food: As a food additive, calcium carbonate can regulate acidity and alkalinity in foods like fruit juices, pastes, and preserves. It can also be used as a raising agent and pH regulator in baked goods. Calcium carbonate is also a food preservative and color retainer, such as when used in organic apples.
• Medicine: As a pharmaceutical product, calcium carbonate can be used as an antacid to treat indigestion and heartburn, and to manage digestive issues like GERD and acid reflux. It can also help treat conditions related to low calcium levels, like osteoporosis and hypothyroidism.
• Construction: Calcium carbonate is used in the manufacturing industry as a building material, such as in marble, quick lime, and cement.
• Cleaning: Calcium carbonate is a mild abrasive agent that can be used to clean and polish delicate surfaces like marble and vitroceramic hobs.
• Other uses: Calcium carbonate is also used in toothpaste, dry-mix dessert mixes, dough, wine, soap, cleaning products, glasses, filtration systems, plastics, and cosmetics. It is also an active ingredient in agricultural lime and animal feed, and is added to swimming pools as a disinfectant and pH corrector.