Help with my science fair project please So my project is the effect of acids on different minerals. Like i would take a weakish acid like say vinegar and pour it on small pieces of mineral (amethyst, azurite, calcite mica, etc.), but the problem is that i don't have a control for the experiment. I think all projects need a control right? I have no clue what to do for this project. Come basilers, help a man in need! thanks in advance!