How to Test a Mineral with HCl, the "Acid Test" to Identify Calcite - for Teachers and Students 

Check out omg.georockme.com for an online practical mineral study guide for students and teachers. The mineral calcite is tested against a cold, dilute (10%) solution of hydrochloric acid (HCl). Observation reveals a reaction that is characteristic of this mineral, and helps in identifying calcite.
Another Geoshort educational video for teachers and students from Scott Brande.
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