# Why do would a mineral such as calcite fizz when a weak acid is dropped on it?

$\text{Calcite mineral}$ is ${\text{CaCO}}_{3}$. This reacts with strong acids.
$C a C {O}_{3} \left(s\right) + 2 H C l \left(a q\right) \rightarrow C a C {l}_{2} \left(a q\right) + {H}_{2} O \left(l\right) + C {O}_{2} \left(g\right) \uparrow$
The effervescence is $C {O}_{2} \left(g\right)$. Of course, $H C l$ is not a weak acid. However, calcium carbonate tends to react with weaker acids such as acetic acid.