What mineral has a hardness of 3 and bubbles with acid?

Calcite is the mineral that has a hardness of 3 on the Mohs scale and reacts with dilute hydrochloric acid, producing effervescence or bubbling. This reaction occurs due to the release of carbon dioxide gas when the acid interacts with calcite's calcium carbonate composition. It is commonly found in sedimentary rocks and can appear in various forms, including crystalline and granular.