Lesson #3: Growing Crystals

Materials: 2 glass jars, salt, sugar, warm water, 2 pencil, and wool.


  1. Students will work in groups of three.
  2. Dissolve as much salt as possible into a jar of warm water. Keep adding and stirring until you can see undissolved salt crystals in the water.
  3. Tie the wool around the pencil so it rests in the salt water. Leave the jar in a cool place.
  4. As the water cools, salt crystals grow on the wool. Each day, pour the water away. Add a fresh batch full of dissolved salt. Day by day, the crystals on the string will get bigger.
  5. Repeat steps 2, 3 and 4 with sugar instead of salt.
  6. Students complete a daily log documenting the growth and change of the crystals, indicating the changes in shape, size, color and other observations.
  7. After a week, the groups will compare the crystals.
  8. Students will draw the crystal formations.

Discussion Questions:

  1. What changes occurred in the jar?
  2. How long did it take for formulate the crystals?
  3. What shapes do crystals form?

Lesson #1: Mineral Identification | Lesson #2: Chalk Painting

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