Before photography was widely used, geologists, astronomers, naturalists and other scientists used words and drawings to inform each other about their discoveries. Have students pretend they are geologists and have them draw pictures of crystals as carefully as they can, including all details. Then, encourage students to color the drawings. The more detail they have included, the more colors they can incorporate. Students can compare these drawings to the actual drawings of birefringent crystals in Activity 16.
Students can include stories about stalactites and stalagmites.
Have students illustrate their stories. An adventure story about young people lost in a cavern could be a launching point to encourage students to do further research on caverns or to write their own stories. Invite a gemologist to speak to the class, display some precious crystals and discuss how the crystals are cut to make them marketable. Try contacting a local jewelry store, geology club, or college or university department. The famous blue Hope Diamond weighs 44.52 carats and is said to be unlucky for its owner.