Rock Cycle - Chemistry (3)

  • Comparing the properties of different elements
  • Discovering properties of compounds.
  • compound
  • element

Students explore the elements that make up minerals.


Minerals are either composed of one type of element (a native mineral) or two or more elements (a compound). The characteristics of minerals depend on their constituent elements and compounds. Table salt (the mineral halite) would not have the same properties if either sodium or chlorine were replaced with another element such as silver or potassium. However, the characteristics of elements are not always expressed in minerals; for example, quartz, a hard, glassy mineral, is composed of silicon, which is a lightweight, metallic element, and oxygen, a clear gas.        

In this exercise, the students will be given the characteristics of several elements, and will then identify those characteristics in a group of minerals. They will learn that elements cannot always be recognized in minerals.


  1. Pass out the Periodic Table Placemats Instruct students to find the following elements on the placemats: iron (Fe), sulfur (S), copper (Cu), silicon (Si), and titanium (Ti). Ask the students to say the atomic symbol of each element. Review the characteristics of each element as outlined below. Have students record the names of the elements in their workbooks.
    heavy, metal
    SULFUR: yellow, bad "rotten egg" smell
    blue-green as a compound with oxygen, copper color as a native metal
    gray, glassy, metallic, light weight
    dark gray or silvery, metallic
  2. Explain the lab. The students should try to determine if the characteristics of the elements described in class are recognizable in the specimens. In other words, the students should try to decide if the individual pieces provide clues to which element they are examining.
  3. Allow the students to look at the mineral samples and try to determine which elements are in which sample. Students should record their guesses in the squares provided on the worksheet.
  4. Here are answers to guide their observations:

    quartz (rose) Si + O, a trace of Ti (gives it the pink color) even though titanium is gray
    S, is naturally yellow and if scratched gives a bad smell (rotten egg)
    Fe + S, called fools’ gold; heavy from Fe and yellow from S
    Fe + O, heavy from Fe
    Cu + Si + O, blue from copper tarnish
    Cu, color is natural copper
    Cu + Fe + O, color from copper, heavy from iron

  5. Have the students write an answer to the conclusion. Make sure they understand that elements are not always identifiable in minerals.

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