This is a property that depends on the chemical composition of the
mineral. Carbonate minerals, which contain (in addition to at least one
other element) three parts of oxygen and one part of carbon, can be
tested with dilute hydrochloric acid. When a drop or two of this acid is
put on a carbonate mineral such as calcite (calcium carbonate, CaCO₃),
the acid begins to bubble and fizz. The fizzing or effervescence is
caused by the carbon dioxide gas that is formed when the acid and
mineral come in contact with each other. This test is also helpful in
identifying rocks, such as limestone and marble, that contain carbonate
minerals.