Earth Materials. John O'Brien

19 explores ores minerals, industrial minerals, and gems as well as environmental and health issues related to Earth materials.

      In addition to information presented in this textbook, additional resources, including detailed descriptions of major rock‐forming minerals and keys for identifying minerals using macroscopic and/or optical methods are available on the website that supports this text at:

      www.wiley.com/go/hefferan/earthmaterials.

      Our overall goal is to produce an innovative, visually appealing, informative, and readable textbook that addresses the full spectrum of Earth materials. We present equal treatment to minerals as well as igneous, sedimentary, and metamorphic rocks and demonstrate their impact on our personal lives and the global environment on this planet. We hope you enjoy this text and use it to further your knowledge of Earth materials.

      Acknowledgments

      The authors thank all those at John Wiley & Sons who worked with them on the second edition. Special thanks are due Rosie Hayden, Antony Samy, Anandan Bommen, Umar Saleem and Andrew Harrison. Their first edition greatly benefited from guidance provided by Ian Francis, Kelvin Matthews, Jane Andrews, Delia Sandford, Camille Poire, Catherine Flack and, once again, Rosie Hayden. The authors are grateful to Anita O’Brien who provided the index for both editions. We once again thank reviewers for the first edition who greatly improved the textbook, while in no way being responsible for its shortcomings. These individuals include Malcolm Hill, Stephen Nelson, Lucian Platt, Steve Dutch, Duncan Heron, Jeremy Inglis, Maria Luisa Crawford, Barbara Cooper, Alec Winters, David H. Eggler, Cin‐Ty Lee, Samantha Kaplan, Penelope Morton and Ellen D’Andrea.

      The authors truly appreciate many individuals and publishers who generously permitted reproduction of their figures and images from published work, educational websites and/or personal collections. The authors are particularly indebted to Doug Moore, Steve Dutch, Stephen Nelson, Kurt Hollacher, Gregory Finn, Patrice Rey, Neil Heywood, the U.S. Geological Survey, the Geological Survey of Canada and the Geological Society of America.

      Kevin Hefferan would especially like to thank his wife Sherri and children Kaeli, Patrick, Sierra, Keegan and Quintin and parents Patrick and Catherine for their love, laughter and never wavering enthusiasm. Kevin is also grateful for the support of the Department of Marine Science, Safety and Environmental Protection at Massachusetts Maritime Academy of Buzzards Bay, MA. Kevin expresses his appreciation to all his collaborative colleagues through the years especially Jeff Karson, Tony Rathburn, William Hubbard, Heather Burton, Abderrahmane Soulaimani, Hassan Admou, Ali Saquaque, Nasrrrddine Youbi, Lucian Platt, Neil Heywood, Keith Rice, Doug Moore and Samantha Kaplan. Kevin was an undergraduate student of John O’Brien at New Jersey City University and greatly benefited from his wisdom as well as that of John Marchisin, Howard Parish and Barry Perlmutter.

      John O’Brien would like to thank his wife Anita, his sons Tyler and Owen and granddaughter Scarlett for their love and support. John worked for 41 years in the Department of Geoscience‐Geography (now Earth and Environmental Sciences) at New Jersey City State University. He is now retired and living in the San Francisco Bay area. Sabbaticals from the University in 2005 and again in 2011, gave John the time required to complete this project. John wishes to acknowledge his indebtedness to Ansel Gooding, Charles Martin, Wayne Martin, John Pope, Robert Webb, John Crowell, Don Runnels, Joe Clark and Barry Perlmutter for encouraging, supporting and challenging him at critical times in his career.

      The authors believe that an understanding of Earth materials is more important than ever in this twenty‐first century in order to appropriately utilize essential resources, for mitigating geohazards and dealing with environmental change. Universities and government agencies would be wise to revitalize the Earth science and geology curricula in the United States and other countries around the world. We must all renew efforts to use our resources wisely and to engage the green economy.

      About the Companion Website

      This book is accompanied by a companion website.

      www.wiley.com/go/hefferan/earthmaterials2

      This website includes:

       Figures and Tables from the book

       Appendices and additional resources, including detailed descriptions of major rock-forming minerals and keys for identifying minerals using macroscopic and/or optical methods

Chapter 1 Earth materials and the geosphere

      1  1.1 Earth materials

      2  1.2 Minerals and mineraloids

      3  1.3 The geosphere

      4  1.4 Detailed model of the geosphere

      5  1.5 Global tectonics

      6  1.6 Hotspots and mantle convection

1.1 EARTH MATERIALS

      This book concerns the nature, origin, evolution, and significance of Earth materials. Earth is composed of a variety of naturally occurring and synthetic materials whose composition can be expressed in many ways. These include their chemical, mineral, and rock composition. In simple terms, atoms combine to form minerals and minerals combine to form rocks. Discussion of the relationships between atoms, minerals, and rocks is fundamental to an understanding of Earth materials, their properties, and the processes that produce them.

1.2 MINERALS AND MINERALOIDS

      The term mineral is used in a number of ways. For example, the chemical elements, such as calcium, iron, and potassium, listed on your breakfast cereal box, your bottle of vitamin supplements or your bag of fertilizer are called minerals. Coal, oil, and gas are referred to as mineral resources. All of these fall under a broad use of the term mineral. In a stricter sense used by many, but not all geologists, minerals are defined by the following properties:

      1 Minerals are solid, so do not include liquids and gases. Minerals are solid because the atoms in them are held together in fixed positions by forces called chemical bonds (Chapter 2).

      2 Minerals are naturally occurring, meaning that they occur naturally within the Earth. This definition excludes synthetic solids that are produced only by technologies in laboratories or factories. It does include solid Earth materials that are produced by both natural and synthetic processes, such as natural and synthetic diamonds and the solid materials synthesized in high temperature and high pressure laboratory experiments that are thought to be analogous to real minerals that occur only in the deep interior of Earth.

      3 Each mineral species has a specific chemical composition which may vary only within well‐defined limits; that is to say that each mineral possesses a chemical