OBJECTIVES:

• Learning that minerals are made of elements.
• Discovering that silicon and oxygen make up quartz.

VOCABULARY:

• compound
• element
• mineral

MATERIALS:

• quartz crystal
• Periodic Table Placemats
• sample of silicon

Students look at a piece of quartz and silicon.

quartz crystals

BACKGROUND:

Children are fascinated by minerals because they are pretty and uncommon in everyday life. Children like to hold them, as if they were magical. You can pick up a mineral and it feels cold, but if you keep it in your hand, it gets warm. Many minerals also have shapes that delight children’s visual perception.

Minerals are composed of one or more elements. Since there are many elements, many combinations are possible. There are thousands of different minerals. Minerals are important in a number of ways. Minerals are the building blocks of rocks. They are important to the world’s economy. Minerals such as gold and silver can determine the wealth of a nation. Other minerals are admired because of their beauty, such as rubies and emeralds. Finally, minerals are very useful in everyday objects such as watches and clocks (quartz) and plaster (gypsum).

PROCEDURE:

1. In this lesson students will learn that minerals are made up of different combinations of elements, which they will learn are called compounds. Tell the children that minerals are an example of solid state matter. They are not liquids or gases. They have definite shapes. Matter is made up of elements. One or more elements make up minerals.
     
2. Introduce the word "COMPOUND," as a substance composed of one or more elements.

   Write on the boards ELEMENT + ELEMENT(S) = COMPOUND. Use a quartz crystal as an example of a compound. Explain to the students that the crystal grew naturally in the earth. The elements silicon (Si) and oxygen (O) joined together [silicon + oxygen] to make QUARTZ (SiO₂). Pass the crystal around so the students can see how it looks and feels. Write down their impressions of this mineral on the board.
    

3. Retrieve quartz crystal from the class and pass out the Periodic Table Place mats. Ask the students if they remember which elements make up the compound quartz. Have the students locate the elements "silicon" and "oxygen" on the place mats.
     
4. Silicon by itself is a shiny, gray substance. Show students the piece of silicon. This is an element that was created in a laboratory. It does not occur naturally. Compare silicon with quartz. It doesn’t have the same appearance. Ask the students to show you oxygen. Hopefully they will point to the air. Oxygen is a clear gas. Together these very different elements combine to form quartz. A solid and a gas form a solid.

   Children may have heard the word "silicon" in association with the computer industry. (Computer chips are presently made largely of silicon). Pure silicon is not a naturally occurring element. Silicon occurs in nature only in combination with other elements, mainly oxygen. Pure silicon is manufactured commercially by heating sand in the presence of carbon.
     

5. Use the periodic table placemat to examine different elements. Ask the students to find elements, like calcium, carbon, or boron. You may want the students to write down the symbols. You may wish to play a "chemical game," having the students find an element that goes with the alphabet like, Arsenic for A, Boron for B, Carbon for C, etc. Students love to find the elements on the chart.

  [Dictionary]  
[Back to Rock Cycle Grid]   [Back to Minerals (1)]