Rock Cycle - Minerals (3B)
Post Lab 

  • Making a crystalline model of salt.
  • Exploring crystals.
  • crystal
  • cube
  • halite

Students make a cubic model of salt.

model of a salt crystal


Review the characteristics of halite, especially its salty taste. Children take salt for granted, but yet it  is a unique compound that is important to many animals including humans. Salt has been very important for humans. Salt was used to preserve food before the refrigerator was invented. Imagine a world without refrigerators! We need a balance of salt in our blood or we would not be able to live.

Although sodium and chlorine are very different elements, they combine to form the compound halite (NaCl). Salt crystals grow and break into cubes because the sodium and chlorine atoms are arranged in what is called "cubic packing". A sodium atom is half the size of an atom of chlorine, so chemically they combine perfectly in a cubic pattern, as shown in the diagram above.

  1. The purpose of this art lesson is to reinforce the concepts presented in the previous labs on crystals. Review that all minerals are crystalline, but only when the minerals have enough room to grow will they exhibit visible crystal shapes.
  2. The Crystal and Gem Eyewitness book will appeal to your students. There are so many stories in the book that we suggest you take one and retell it to the students. Children are sure to tell you about their jewelry at home.
  3. In the next part of the exercise, students will make a model of a halite crystal. You may want them to color the crystals different colors. Salt is naturally clear, white, or pink. Salt will take on any natural dye, so it can be any color.
  4. Students should color the crystal before they cut it out. After cutting, the students should fold the model along the black lines, using a straight edge. If folded correctly, the crystal will go together easily. Finally, students can glue or tape the tabs in place.



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