The Composition of Rocks and Minerals

NC Standard:  2.03

Activity:  What type of crystals do rocks have?

Question: Are rocks made of crystals?

Vocabulary: Crystals, geodes

Materials: Collection of rocks and a hand lens or magnifying glass

Background: This activity can be done using the same collected tocks ued in the classification activity. Igneous and metamorphic rocks have undergone intense heat in their formation and the crystals are interlocking, or melted together by nature, with materials that settled to the bottom of a body of water where the rock was formed. Beautiful arrangements of quartz crystals are found in the centers of hollow rocks called geodes. Try to include at least one geode in the collection used.

Procedures:

• 1. Examine each rock with a magnifying glass or hand lens.

• 2. Record any crystal structure you see. Are the crystals lined up or are they arranged randomly? Do the crystals seem to be interlocking (melted together) or do they appear to be glued together by a cementing material?

• 3. Put the rocks in groups according to your findings.  
  

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Line of Learning:  This line is drawn to provide students with a space to share their experimental learning in words or pictures.
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