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Individual Contributors. 5

Contributing Schools and Organizations. 5

Preface. 6

Introduction.. 7

The Priday Bed, Oregon stratigraphy. 8

Lithophysae waterlines. 8

Lithophysae star cores. 10

Cogenesis. 12

The Stendel Deposit, New Mexico.. 12

Cogenesis of rhyolite, perlite, and lithophysae. 15

Thunderegg emplacement—depletion zones. 15

Tiltage thundereggs. 16

Lithophysae hot gel theories. 17

Lithophysae—infilling of gas cavities. 18

Chapter 1.  Granite Precursor and Types of Rhyolite-Obsidian Lava Flows  19

Background—the lavas. 19

Lithophysae formation in domes and flows. 20

Mixed flows of rhyolite and preperlite. 27

Flows of rhyolite over perlite. 29

Summary. 31

Chapter 2.  The Appearance of Immiscibility in the Field:  Welded Tuff or Lava Flows and Devitrification at Solidus or Liquidus?. 32

Problems with ash-flow tuff models. 32

Problems with quenching models. 36

Water in rhyolitic lava.. 37

Spherulites in liquidus. 41

Cristobalite as the texture former. 44

Chapter 3.  The Dominant Mineral in the Formation of Spherulitic Textures  47

The role of cristobalite. 48

Fronts of spherulitic crystallization.. 50

Box core and box cavity structures. 55

Chapter 4.  The Exsolution of Volatiles and Growth of Spherulites and Lithophysae:  The Sequential Diagrams of Lithophysal Cavity Types. 58

Spherulite formation.. 58

Crystallization and lithophysa inception model. 61

Crescent cavity formation model. 64

Box core development model. 65

FOSC formation model. 71

Biconoid formation model. 73

Triconoid formation model. 75

Box cavity formation model. 76

Star-vectored cavity formation model. 79

Chapter 5.  How to Determine Interior Core Structures for Correct Cutting Orientation:  Some Examples of Mining and Cutting Successes and Failures. 80

Cutting biconoids. 80

Templeton, California biconoids. 82

Radium Springs, New Mexico biconoids. 84

Other biconoids. 85

Lithophysae pressure ridges and pressure channels  85

Quinn River, Oregon amygdaloids. 87

Determining specimen cutting orientation.. 88

Chapter 6.  Exterior Morphology of Thundereggs and Matrix Types:  Clues for Successful Mining and Cutting   90

Porphyritic lithophysae. 90

The Black Agate Mine, Wiley’s Well, California geology  92

Marking thundereggs for cutting.. 96

China Lake, California thundereggs. 98

Aurora, Nevada thundereggs. 98

Aphanitic lithophysae. 99

The Black Rock Desert, Nevada thundereggs. 100

Cutting torpedo lithophysae. 102

Cutting stalactite lithophysae. 103

The Baker Egg Lode Mine geology and thundereggs  103

The Secret Ridge Mine, Oregon thundereggs. 109

Flow-banded thundereggs: Dugway Geode Beds, Utah and Pike Creek, Oregon   110

The Radford Mine, Oregon thundereggs. 110

The White Rock Spring, Oregon thundereggs. 111

The White Fir Spring, Oregon thundereggs and biconoids  112

Chapter 7, Part One:  Transitional Nodules:  Regional and Isolated Similarities in Composition and Structures and where they Occur. 114

McDermitt, Oregon transitional nodules. 114

Barstow, California transitional nodules. 115

The Calico Mountains, California transitional nodules  118

Opal Mountain, California transitional nodules. 119

Newberry, California transitional nodules. 122

Rip Van Winkle Mountain, California transitional nodules  123

Transitional nodule geology. 124

Chapter 7, Part Two: Isolated and Regional Similarities Affecting Lithophysal Rhyolite  126

The Potato Patch, Wiley’s Well, California thundereggs  126

The Donnybrook Bed, Oregon thundereggs. 128

The Marsing, Idaho thundereggs. 130

The Laton Point, Oregon thundereggs. 131

The Harper, Oregon thundereggs. 134

The British Columbia, Canada thundereggs. 134

The Coast Range, California marcasite thundereggs  134

Chapter 7, Part Three: Summary of Igneous Processes and Products  137

Chapter 8.  Diagenesis of Amorphous Silica:  Hydrothermal and Meteoric Emplacement in Lithophysal Cavities  138

Silica chemistry. 139

Models of waterline formation in lithophysae. 140

Thundereggs with precious opal. 146

Diffusion and fill tubes in lithophysae. 148

The role of meteoric water. 149

Axiolite lithophysae. 152

Hydrothermal chalcedony. 154

Radium Springs, New Mexico thundereggs. 155

Hydrothermal quartz. 156

Chapter 9.  Inclusions: Colors, Moss, Plumes, Dendrites, Sagenite, Crystals, Casts and Pseudomorphs  159

Order of deposition of inclusions. 159

Calcite and Aragonite. 160

Moss agate. 165

Chalcedony and quartz stalactites. 166

Angel-wings. 167

Plumes, Dendrites. 169

Sagenite inclusions (zeolites) 170

Mineral zoning, and shadow agates. 174

Morrisonite and Bruneau jaspers. 180

Chapter 10.  Summary of Diagenesis and Inclusions. 182

Chapter 11.  How to use Topographic and Geologic Maps and Sizes Available from the U.S.G.S. 183

Appendix A.  Specimen Photographs and Identifications from the collection at the Deming-Luna Membres Museum    185

Appendix B.  Thundereggs from other Countries. 219

Appendix C.  Some of the very best from the Baker Egg Lode Mine Discovered Circa 1950 and in Operation from 1975 to the Present. 221

Appendix D.  A Selection of Related Amygdaloids, Agates, and Other Geode Types  225

Appendix E.  A Selection of Petrified Wood.. 239

Appendix F. 244

Appendix G.  Priday Ranch Clay XRD Analysis. 245

Appendix H.  Priday Ranch Lithophysal Shell XRD Analysis  246

Appendix I.  John Day Formation XRD Analysis. 247

Appendix J.  John Day Formation XRD Analysis. 249

Appendix K.  Panum Crater XRD Analysis. 249

Locations Appendix (1/6) 250

Locations Appendix (2/6) 251

Locations Appendix (3/6) 252

Locations Appendix (4/6) 253

Locations Appendix (5/6) 254

Locations Appendix (6/6) 255

References. 256

Glossary. 258

Index  264

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