Let’s Review For Your Test
Pages 70-71, #1- 3, 6-9, 12-14, 17, 18, 22, 23, 25-29
Pages 98-99, #1-5, 6-8, 11-15, 18-28
Pages page 70-71, #1- 3, 6-9, 12-14, 17, 18, 22, 23, 25-29
1. In a mineral, the particles line up in a repeating pattern to form
– B. A Crystal
2. The softest mineral in the Mohs hardness scale is
– B. Talc
3. Halite is a mineral formed by
– C. Evaporation
6. Luster is the term that describes how a mineral reflects light
from its surface.
– True
7. A piece of unglazed tile is used to test a mineral’s hardness
– False – Streak
8. If magma cools very slowly, minerals with small crystals form
– False – Large
9. Minerals form from hot-water solutions at chimneys on the
ocean floor
– True
Pages page 70-71, #1- 3, 6-9, 12-14, 17, 18, 22, 23, 25-29
12. How can the streak test be helpful in identifying minerals?
Although the color of a mineral may vary, the color of a mineral’s streak is
always the same.
13. Compare cleavage and fracture.
Cleavage is when a mineral splits easily along flat surfaces. Fracture, by
contrast, describes how a mineral breaks apart when it does not split evenly.
14. Describe two different ways that minerals can form.
In general, minerals can form through crystallization of melted materials and
crystallization of materials dissolved in water. In the first way, minerals form as
hot magma cools deep inside the crust or as lava hardens on the surface. In
the second way, minerals crystallize as solutions cool or evaporate.
17. Color and luster are both properties of minerals. How are these properties similar?
How are they different? How can each be used to help identify a mineral?
Color and luster are similar in that they are both visually observable properties. There
are fewer kinds of luster, however, than there are colors. Luster is also different in
that it can describe the surface texture of a mineral.
False – Streak
Pages page 70-71, #1- 3, 6-9, 12-14, 17, 18, 22, 23, 25-29
18. Obsidian forms when magma cools very quickly, creating a type of
glass. In glass, the particles are not arranged in an orderly pattern as in
a crystal. Obsidian is a solid, inorganic substance that occurs naturally
in volcanic areas. Should it be classified as a mineral? Explain why or
why not.
Since obsidian does not have a crystal structure, one of the five
characteristics of a mineral, it cannot be classified as a mineral.
22. Describe wulfenite’s color, luster, and crystal structure.
The color of the sample of wulfenite is yellowish orange, the luster is
shiny and gemlike, and the crystal structure appears to be rectangular,
with angled edges.
23. Did the wulfenite form slowly or quickly? Explain your answer.
The fairly large size of the crystals indicates that the wulfenite formed
slowly.
25
Pages page 70-71, #1- 3, 6-9, 12-14, 17, 18, 22, 23, 25-29
25. Which mineral in the table could be scratched by all the
others?
– D. Talc
26. The mineral in the table with the greatest density.
– A. Copper
27. To be suitable as a gemstone, a mineral usually must be very
hard and have a glassy luster. Which mineral on the list would
probably make the best gemstone?
– B. Corundum
28. Quartz and talc both produce a white streak and have similar
density. What property or properties could you easily test to
tell them apart?
– A. Hardness and Luster
29. Suppose that you have found a dense, dark colored mineral
with a metallic luster. What property would you test quickly
and easily to determine if the mineral were copper rather
than galena?
– C. Streak
Pages 98-99, #1-5, 6-8, 11-15, 18-28
1. Which of the following sedimentary rocks is a chemical rock?
– C. Rock Salt
2. Metamorphic rocks can be formed from
– D. All rock groups
3. The rock formed when granite changes to a metamorphic rock is
– C. Gneiss
4. Which of the following helps create both metamorphic and
sedimentary rocks?
– B. Pressure
5. Millions of years ago, a deposit of organic limestone was probably
– C. A Coral Reef
6. Igneous rocks are classified by how they formed and by their color,
texture, and shape.
– False – Mineral Composition
7. Granite is a fine-grained igneous rock
– False – Coarse-grained
8. Sedimentary rocks that form when minerals come out of solutions are
classified as porphyritic.
– False – Chemical rocks
Pages 98-99, #1-5, 6-8, 11-15, 18-28
11. What is the relationship between an igneous rock’s texture and where it was
formed?
An igneous rock with a glassy or fine-grained texture cooled rapidly near the
surface. An igneous rock with coarse-grained texture cooled slowly deep
underground. An igneous rock with a porphyritic texture cooled in two stages, first
far below the surface and then nearer to the surface.
12. Why can water pass easily through sandstone but not through shale?
Water can pass through sandstone because the cementation process does not fill
all the spaces between sand grains, leaving small connected holes. In shale, the
spaces between the clay particles are too small for water to pass through.
13. Describe how a rock can form by evaporation. What type of rock is it?
A rock can form by evaporation when a sea or lake evaporates, leaving mineral
deposits. Rock salt and gypsum are examples of rocks formed by evaporation.
14. How do the properties of a rock change when the rock changes to metamorphic?
When rock changes into metamorphic rock, its appearance, texture, crystal
structure, and mineral content change.
15. What are the sources of the heat that helps metamorphic rocks to form?
Forces inside Earth push rock down toward the heat of the mantle. Pockets of
magma rising through the crust also provide heat that can produce metamorphic
rock.
Pages 98-99, #1-5, 6-8, 11-15, 18-28
18. As a geologist exploring for rock and mineral deposits, you come across an area where the
rocks are layers of coal and shale. What kind of environment probably existed in this area
millions of years ago when these rocks formed?
The environment was probably swampy, since coal forms from swamp plants buried in water.
The shale is further evidence of a wet environment, since it forms from clay particles
deposited by water.
19. How are clastic rocks and organic rocks similar/different?
Clastic rocks and organic rocks are similar in that they are both sedimentary rocks composed
of sediments deposited in layers. They are different in that clastic rocks are formed when
rock fragments are squeezed together, while organic rocks are formed when the remains of
plants and animals are deposited in layers.
20. In the rock cycle, igneous, metamorphic, and sedimentary rocks can all become magma again.
What step in the rock cycle causes this to happen? Explain your answer.
Melting is the step in the rock cycle by which rocks become magma again. Melting occurs
when forces inside Earth push rocks deep beneath the surface. The rocks melt and form
magma. When magma cools, it produces new igneous rock.
21. How would you describe the texture of each rock?
Rock A – foliated rock with a coarse-grained texture
Rock B – coarse-grained texture
Rock C – coarse-grained crystals mixed with fine-grained crystals
22. Which of the three rocks would you classify as a metamorphic rock? Explain your answer.
Rock A is a metamorphic rock because it is the only one of the three that is foliated.
Pages 98-99, #1-5, 6-8, 11-15, 18-28
24. A good title for this diagram is
– D. Pathways of the Rock Cycle
25. The process shown by letter A is called
– C. Erosion
26. The process shown by letter B involves
– B. Heat and Pressure
27. According to the diagram, metamorphic rock
forms from
– A. Igneous rock and Sedimentary rock
28. According to the diagram, magma and lava may
form through the melting of
– A. Any type of rock