Here's why:
* Calcite is a carbonate mineral. This means it contains the carbonate ion (CO₃²⁻).
* Carbonates react with acids. When dilute acid (like hydrochloric acid) is applied to calcite, the acid reacts with the carbonate ion to produce carbon dioxide gas (CO₂).
* Effervescence is the release of gas. The carbon dioxide gas bubbles out of the solution, causing the characteristic fizzing or effervescence.
Other carbonate minerals like dolomite will also display effervescence with acid, but calcite is the most common and readily recognizable for this reaction.
