Directed Reading Handout on Mineral Formation
Name _____________________________ Date ______
Part 1. Here is a list of descriptions (a-f) of six ways minerals form. Look at the diagram in the reading (pp. 1213) that shows important clues about each. Write one word from the word bank that you think matches the
description the best.
Word Bank Name : Evaporites, Precipitates, Metamorphics, Hydrothermals, Pegmatites, Plutons
Surface or Deep: From the diagram decide whether this type of mineral would form at or near the earth’s
surface or deeper underground (S for at or near the surface. D for deeper underground.)
#
Description
a
Minerals that form pressure, heat and
chemical changes deep inside the earth
b
Minerals in hot ground water solutions that
crystallize in cracks in the bedrock.
c
Minerals that evaporate out of water on a
shallow lake bed.
d
e
f
Word Bank Name
Surface or
Deep
Minerals that crystallize as underground
magma rises upward in the presence of hot
fluids
a. Minerals that crystallize as a large body
of magma reaches the surface and cools very
slowly.
Minerals that settle out of water either in
caves or the bottom of a shallow lake or
sea.
Critical Thinking:
Find answers in the reading and picture description.
1. Suppose you find a mineral crystal that is as tall as you are. What kinds of environmental factors would
cause such a crystal to form? (Look through Diagrams of Mineral Formations p.12-13)
2.
In some environments it is so dry that lakes form dry lake beds without any water. If you found a
mineral such as gypsum in a dry lake bed how would it have most likely formed?
3. Which of the following is NOT important in the formation of minerals? (circle your answer)
A. Heat
B. volcanic activity C. presence of ground water D. wind
4.
Minerals can form in these small teardrop-shaped formations called ____________________
Part 2. Mineral Detective: Choose the name of a mineral in Column B that best matches the description
of how it formed in Column A, and write the corresponding letter in the space provided in Column A.
Column A
Column B
____ 1. Forms from slowly cooled magma that solidifies into a pluton
a.
____ 2. Forms from ground water heated by magma near the earth’s surface.
b. Garnet ___
____ 3. Forms in tear-shaped formations in the presence of magma and hot fluids.
c. quartz ___
____ 4. Forms in metamorphic rock under great pressure
d. gypsum ___
____ 5. Forms from materials in cool surface water that evaporate
e. dolomite ___
____ 6. Forms in caves and at the bottom of lakes and seas.
f. Topaz ___
Gold
___
7. What is the difference between a pegmatite and a pluton?
8. Concept Mapping: Use the following terms to complete the concept map below: Lakes and seas, cooling,
chemical composition, evaporates, hot water solutions.