Describing+Minerals+Color


 * Learning Experience 5: Minerals’ Color**

Materials:
 * White streak plates
 * Black streak plates
 * Mineral sample baskets

Learning Targets:
 * 1) I can do a streak test on a mineral.
 * 2) I can compare the outside color of a mineral to its streak test color.

Procedure:
 * 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) Explain that the streak test is one way of doing this. 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.
 * 4) Show them how to use colored pencils and words on 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.
 * 5) Send pairs / small groups off to work on their streak tests.
 * 6) Come back together to share results and fill out the class chart (page 62). Return to guessing game from the beginning, and tell them that the observable color of the mineral is gray, but its streak color is white. They should be able to guess that it is fluorite.