Erik and Erika,two young mineral fanatics,have discovered some treasures.Answer the question on this page about what they have found.To do this you will need to pay attention to what you have learned in class,the hardness scale to the right,are “Physical Properties of Some Common Minerals”the chart on the back of this page.
1.Erik has a handful of whitish-grey stones with a nonmetallic luster that leave a colorless streak. They can be scratched by a steel file but not by a knife.
What does he have?
2.Both kids have found samples of a red mineral which leaves a gray streak. It can be scratched with 2 can be scratched by fingernail and with a penny,and it can be easily cut with a knife.
What is it?
3.Erika is holding a very soft mineral that leaves black “grease” on her fingers. It makes a black streak and has a shiny luster. What is it?
4.A pale while stone is found at Erik’s feet. It has hexagonal crystals, leaves a white streak, and can be scratched by a knife, but not by a fingernail. Could it be dolomite?
5.Erika finds a colorless chunk of mineral. It cannot be scratched by calcite. It has no shine to it, and seems to break apart in many directions. What has she probably found?
6.Erik has found a deep red mineral that looks like a gem. It leaves a colorless streak and is harder than quartz. Could it be a garnet?
7.A brown mineral that leaves a brown streak is in Erik’s basket. It fractures irregularly and can be scratched by a steel file but not by a knife.It has a metallic luster. What might it be?
8.Erika has some yellow stones that leave a yellow streak. They can be scratched with a fingernail. She wonders if they could be gold, but they do not have a metallic luster. What might they be?
9.Erik’s mother has let him examine a gem she has. It is blue, leaves a colorless streak, and cannot be scratched with anything they find. It does scratch quartz. What might it be?
10.Erika thinks she has found some copper. The mineral looks coppery-red, and can be scratched by fluorite. It has a metallic luster. Is this probably copper?
11. A yellow gem that Erika has seems to be a topaz. If it is, will it scratch a steel file?
12.The pair has happened upon a small amount of a shiny, silvery-white mineral that leaves a light gray streak. It is hard enough to scratch calcite. Could it be silver?