What type of gem melts in vinegar?

Here's why:

* Calcite's Composition: Calcite is a type of calcium carbonate (CaCO3).

* Vinegar's Acidity: Vinegar contains acetic acid, which is a weak acid.

* Chemical Reaction: When calcite comes into contact with vinegar, the acetic acid reacts with the calcium carbonate. This reaction produces carbon dioxide gas (which you might see bubbling), water, and calcium acetate.

Important Note: While calcite will react and dissolve in vinegar, it doesn't truly "melt" in the same way that other materials do. The reaction breaks down the calcite structure, dissolving it into its constituent parts.