Lesson Summary Students are introduced to the unique property of the mineral calcite.  Calcite is the only mineral that fizzes when it comes in contact with vinegar.  Students drop calcite in vinegar, observe the reaction, then place 4 more rocks in vinegar to compare the results and predict about which rocks contain calcite. Teacher Background Calcite is the only mineral that has the unique property of effervescing with cold acids.  Real geologists use acids to check for the presence of the mineral calcite in rocks.  Vinegar is a safe cold acid for classroom use.  A steady stream of fizzing indicates the presence of calcite.  Intermittent bubbles are more indicative of air pockets.  Calcite is one of the most common materials on Earth.  Some of the results from this part of the investigation may be inconclusive for the students, or group results may vary.  Students will take the investigation one step further in the next part to confirm the presence of calcite. Set-up/Management Tip Students will be using syringes again.  Have plenty of paper towels ready. The vinegar smell can become quite strong, especially when the windows have to stay closed. Make sure rock samples have not been used too many times.  It helps to “rough” up pieces of calcite and rock samples a bit with sandpaper before the investigation. Literacy Support Books Available Through VAST Mediagraphies: (see Literacy Links) Science Stories “Old Man and the Rock: A Native American Tale” Word Wall/Word Bank The following words are key vocabulary words that will be introduced in this lesson and reinforced throughout the unit: basalt Sandstone limestone vinegar marble acid