Describing+Minerals+Color+and+Luster


 * Learning Experiences 5-6: Streak Color and Luster**

Materials:
 * White streak plates
 * Black streak plates
 * Mineral collections in small containers, one per pair
 * Class chart of mineral attributes (see book)
 * Class chart for examples of glossy, dull, and metallic
 * Examples of glossy, dull, and metallic things
 * Penlights or flashlights
 * Big version of the recording sheet
 * Copies of the recording sheet [|streak color and luster.doc]

Learning Targets: >
 * 1) I can describe a mineral using what I learn from mineral tests.
 * 2) I can describe the streak color of a mineral.
 * 1) I can describe the luster of a mineral.

Procedure: //Before this lesson, at Morning Circle:// Dull = not shiny (like the rug), glassy = like ice cubes, or the white board, etc; metallic = like the chair legs, like the metal magnets, etc. Chart these examples so they can remember. 2. Have a container of all kinds of objects (not rocks or minerals) in the middle of the rug. Have students pick one and say its luster, instead of a greeting. They must say, "The luster is ..."
 * 1) Define the words “dull,” “glassy,” and “metallic” together. Have examples of each one to show them and talk about.

//During geology:// > “Luster is a word for how shiny a material is.” > Explain that scientists test the luster of things by shining a light on them.
 * 1) Hide a mineral in a paper bag. Play a guessing game by saying the color of the mineral: it is gray like ___ (something in the room). Students try to guess which mineral it is.
 * 2) They will realize that they can’t figure it out by color alone because fluorite and graphite are so similar in color. Tell them geologists are always trying to identify minerals when they find them, and they have special tests to help them figure out which mineral is which, since some of them look a lot the same.
 * 3) Introduce the first learning target and explain that they will do what real geologists do to be able to describe more properties of minerals!
 * 4) Introduce the 2nd learning target, and explain that the streak test is one test geologists use on minerals. Demonstrate how to scrape the mineral across the plates to see what color the streak is. Remind them they must use both plates to see which works best for each specific mineral.
 * 5) Show them how to use the Recording Sheet to compare what the minerals look like on the outside (the observable color) with the color of the streak test. Demonstrate and complete a large version of the recording sheet with one or two minerals.
 * 6) Introduce the 3rd learning target and explain that the luster test is another test geologists use on minerals.
 * 1) Give directions for testing luster of minerals using penlights or flashlights. Model filling out the recording sheet. They must put either an X or a Yes in each box.
 * 2) Send pairs / small groups off to work on their tests.
 * 3) Come back together to share results and fill out the class chart (page 62). Do a guessing game where you say "My mystery mineral has a streak color of... and a luster of..." They use the class chart to figure it out. Model how and then have them try it, whispering their answers to a partner before sharing.