General terms:
* Limestone: This is the most common synonym, referring to the sedimentary rock composed mainly of calcium carbonate.
* Calcite: This is the mineral form of calcium carbonate.
* Chalk: This is a soft, white variety of limestone.
Chemical terms:
* CaCO3: This is the chemical formula for calcium carbonate.
Other specific terms:
* Precipitated calcium carbonate: This refers to calcium carbonate produced artificially.
* Ground calcium carbonate: This refers to calcium carbonate that has been ground into a fine powder.
Informal terms:
* Antacid: Calcium carbonate is used as an antacid to neutralize stomach acid.
* Shell material: Calcium carbonate is the primary component of the shells of many marine organisms.
Ultimately, the best synonym for calcium carbonate depends on the specific context and the nuance you want to convey.