Crystal Growing

• Understanding crystal growth is an important part of earth science. Produce crystals in the classroom by dissolving materials such as salt, washing soda, alum or sugar in hot water. When spread thinly over a flat surface or used to soak strings, the solution should then grow crystals. As the solution dries, crystals will form. Use this experiment to help solidify concepts of crystal formation and the role of crystals in the earth's processes.
  
  

Mineral Hardness

• After explaining the concept of a hardness scale of minerals, supply your students with various hard and soft minerals and a few simple scratch tools, such as iron nails and quartz crystals. Label the specimens for ease of identification. Have your students attempt to scratch each specimen to create their own hardness scales. Address the ways in which hard and soft minerals interact to create common geological features. Compare the experimental results to existing hardness scales.
  
  

Microscopy

• Close examination of mineral structures can help reinforce concepts of mineral formations and the three types of rock. After going over the formation processes of sedimentary, metamorphic and igneous rock, provide samples of each along with powerful magnifying glasses or simple microscopes. Have the students closely examine the mineral structures and compare them to the descriptions of minerals in their textbooks. Have students classify each mineral as sedimentary, metamorphic or igneous, then go over the features which identify each mineral. For best results, choose specimens with marked examples of each identifying feature.
  
  

Pumice

• Pumice stone can be an interesting addition to a volcanology unit. Demonstrate the buoyant properties of pumice in a large beaker, along with minerals of similar appearance but greater density. Have the students weigh the specimens and form a hypothesis regarding the buoyant properties of pumice. Use the pumice samples to illustrate some of the processes which occur during volcanic eruptions, as well as the different materials which can result.