How to Perform the Geology Fizz Test without Hydrochloric Acid

Geologists love testing rocks and minerals and, admittedly, one of the most fun tests is the FIZZ TEST. The mineral calcite is made of calcium carbonate (CaCO3).

Hydrochloric acid is the most common acid used among geologists to test whether a rock has any calcite content. In this reaction, the calcium carbonate reacts with the acid and produces carbon dioxide gas, water, and calcium chloride. The carbon dioxide produces the bubbles that you see on the surface of the rock.

The Fizz Test for Limestone & Marble Rocks

Many rocks can look alike. Sometimes telling the difference between a limestone or marble and other rocks such as shale and quartzite can be difficult. One way geologists test the rocks is by performing the acid or “Fizz” test. Calcite is the main component of limestone rocks and its varieties like oolitic limestone, fossiliferous limestone, coquina and marble. The calcite mineral is made of calcium carbonate which reacts with acid. Other varieties of calcium carbonate minerals such as aragonite and dolomite will also fizz during this test.