Department of Earth Science |Northeastern Illinois University

ESCI 121
Fall 2006

Review Sheet for Exam #2  (October 12, 2006)                                                             Dr. Sanders

For the exam, you should be able to do the following:

*  Explain what a mineral is, listing the characteristics that all minerals share. 

*  Explain how a mineral is different from a rock.

*  Explain how to evaluate the mineral properties listed below for a given mineral sample.

           q hardness         q luster         q streak         q specific gravity (similar to density)    
      q cleavage         q color       q solubility       q odor

*  Using a mineral identification key, determine the name of a given mineral sample based on its properties.  (For fun, visit the online mineral identification key provided by the Mineralogical Society of America!)

Sedimentary Rocks and Minerals

*  Examine and describe the properties of the common minerals that occur in sedimentary rocks.  (Examples used in class: sample numbers 7, 8, 14, 17, 18, 19, 20, 21, 30, 33, 34, 35, and 44.)

*  Explain what samples 7, 17, 19, and 20 have in common.

*  Explain what samples 18, 21, 30, and 35 have in common.

*  Explain what samples 8, 14, 33, 34, and 44 have in common.

*  List and describe the two main categories of weathering (chemical weathering and mechanical weathering), and give a few examples of each type.

*  Distinguish between chemical sediments and detrital sediments, describing characteristics of each category and telling how they form.

*  Explain the difference between gravel, sand, and clay sediments.

*  Explain the steps in forming deposits of sediments, including weathering, erosion, transport, and deposition.

*  Explain the steps in forming sedimentary rocks from sediments, correctly using the term lithification.

*  Examine hand samples of sedimentary rocks, describe their textural features. 

*  Using the sedimentary rock key in your textbook on p. 63, identify hand samples of sedimentary rocks and explain how you arrived at each name.

Igneous Rocks and Minerals

*  Sort and classify samples of igneous rocks.

*  Use simple laboratory tools (dissecting needle, copper penny, hand lens, scratch plate, streak plate) to investigate the properties of common igneous rock-forming minerals.

*  Use a mineral identification key to identify hand samples of common igneous rock-forming minerals.  (Examples used in class: sample numbers 3, 4, 5, 9, 24, 30, 31, and 45.)

*  Explain the relationship between cooling rate and crystal size.

*  Define and describe what is meant by the terms plutonic and volcanic as they apply to igneous rocks.

*  Define and describe what is meant by the terms intrusive and extrusive as they apply to igneous rocks.

*  Define and describe what is meant by mafic and felsic mineralogic compositions of igneous rocks.

*  Use a rock key to identify hand samples of igneous rocks.  (Examples used in class: 102, 117, 124, 130, 136, 137, 138, 139, 142, 143, 149, 152, and 157.)

Department of Earth Science | Northeastern Illinois University

© 2006 Laura L. Sanders.  Last updated October 10, 2006.