Crystallizing Minerals from Aqueous Solutions
Students dissolve selected salts and other compounds in water, let the water evaporate, and examine the crystals that grow.
This exercise is designed for a mid/upper-level undergraduate geology course on the principles of mineralogy.
Skills and concepts that students must have mastered
Students should have knowledge of basic chemistry and of minerals equivalent to what they would learn in an introductory geology class.
How the activity is situated in the course
This activity is the 7th of 36 mineralogy exercises and is used towards the beginning of the course.
Content/concepts goals for this activity
- Learn about ways minerals crystallize from aqueous solutions.
Higher order thinking skills goals for this activity
- Learn to think about crystal shapes and classify them in a logical way.
Other skills goals for this activity
- Continue to improve experimental technique.
Description of the activity/assignment
Students dissolve selected salts and other compounds in water, let the water evaporate for about three weeks, and examine the crystals that grow. Students then draw crystal shapes and discuss the experiment. Discussion can include why and how crystals grow from solutions, why some minerals dissolve well and others do not, concepts of symmetry, and crystal systems and point groups.
Determining whether students have met the goals
Hold a class discussion based on this experiment.
Download teaching materials and tips
- Notes for instructors (Acrobat (PDF) 12kB Jul7 05)