ALBERT

Description / Table of Contents: We seek to understand the timing and processes by which our solar system formed and evolved. There are many ways to gain this understanding including theoretical calculations and remotely sensing planetary bodies with a number of techniques. However, there are a number of measurements that can only be made with planetary samples in hand. These samples can be studied in laboratories on Earth with the full range of high-precision analytical instruments available now or available in the future. The precisions and accuracies for analytical measurements in modern Earth-based laboratories are phenomenal. However, despite the fact that certain types of measurements can only be done with samples in hand, these samples will always be small in number and not necessarily representative of an entire planetary surface. Therefore, it is necessary that the planetary material scientists work hand-in-hand with the remote sensing community to combine both types of data sets. This exercise is in fact now taking place through an initiative of NASA's Curation and Analysis Planning Team for Extraterrestrial Materials (CAPTEM). This initiative is named "New Views of the Moon: Integrated Remotely Sensed, Geophysical, and Sample Datasets." As preliminary results of the Lunar Prospector mission become available, and with the important results of the Galileo and Clementine missions now providing new global data sets of the Moon, it is imperative that the lunar science community synthesize these new data and integrate them with one another and with the lunar-sample database. Integrated approaches drawing upon multiple data sets can be used to address key problems of lunar origin, evolution, and resource definition and utilization. The idea to produce this Reviews in Mineralogy (RIM) volume was inspired by the realization that many types of planetary scientists and, for that matter, Earth scientists will need access to data on the planetary sample suite. Therefore, we have attempted to put together, under one cover, a comprehensive coverage of the mineralogy and petrology of planetary materials. The book is organized with an introductory chapter that introduces the reader to the nature of the planetary sample suite and provides some insights into the diverse environments from which they come. Chapter 2 on Interplanetary Dust Particles (IDPs) and Chapter 3 on Chondritic Meteorites deal with the most primitive and unevolved materials we have to work with. It is these materials that hold the clues to the nature of the solar nebula and the processes that led to the initial stages of planetary formation. Chapter 4, 5, and 6 consider samples from evolved asteroids, the Moon and Mars respectively. Chapter 7 is a brief summary chapter that compares aspects of melt-derived minerals from differing planetary environments.

Description / Table of Contents: The Mineralogical Society of America sponsored a short course for which this was the text at Stanford University December 9 and 10, 1995, preceding the Fall Meeting of the American Geophysical Union and MSA in San Fransisco, with about 100 professionals and graduate students in attendance. A silicate melt phase is the essential component of nearly all igneous processes, with dramatic consequences for the properties of the Earth's interior. Throughout Earth history and continuing to the present day, silicate melts have acted as transport agents in the chemical and physical differentiation of the Earth into core, mantle and crust. The occurrence of such magmatic processes leads to the definition of our planet as "active," and the resulting volcanism has a profound impact on the Earth's atmosphere, hydrosphere and biosphere. Although near-surface melts are observed directly during volcanic eruptions, the properties of magmas deep within the Earth must be characterized and constrained by laboratory experiments. Many of these experiments are designed to aid in developing an atomic level understanding of the structure and dynamics of silicate melts under the P- T conditions of the Earth's crust and mantle, which will make extrapolation from the laboratory results to the behavior of natural magmas as reliable as possible. Silicate melts are also the archetypal glass-forming materials. Because of the ready availability of raw materials, and the ease with which molten silicates can be vitrified, commercial "glass" has necessarily implied a silicate composition, over most of the history of glass technology. The properties of the melt, or "slag" in metallurgical extractions, determine the nature of the glass formed, and the needs of the glass industry have provided much of the impetus for understanding the structure-property relations of molten silicates as well as for the glasses themselves. It is now recognized that any liquid might become glassy, if cooled rapidly enough, and understanding the thermodynamic and kinetic aspects of the glass transition, or passage between the liquid and glassy states of matter, has become a subject of intense interest in fundamental physics and chemistry. Glasses have also been studied in many geochemical investigations, often as substitutes for the high temperature melts, with the results being extrapolated to the liquid state. In many cases, in situ techniques for direct investigation of these refractory systems have only recently become available. Much valuable information concerning the melt structure has been gleaned from such studies. Nevertheless, there are fundamental differences between the liquid and glassy states. In liquids, the structure becomes progressively more disordered with increasing temperature, which usually gives rise to major changes in all thermodynamic properties and processes. These changes must, in general, be investigated directly by in situ studies at high temperature. Studies of glass only represent a starting point, which reflect a frozen image of the melt "structure" at the glass transition temperature. This is generally hundreds of degrees below the near-liquidus temperatures of greatest interest to petrologists. Since the early 1980s, a much deeper understanding of the structure, dynamics, and properties of molten silicates has been developed within the geochemical community, applying techniques and concepts developed within glass science, extractive metallurgy and liquid state physics. Some of these developments have far-reaching implications for igneous petrology. The purpose of this Short Course and volume is to introduce the basic concepts of melt physics and relaxation theory as applied to silicate melts, then to describe the current state of experimental and computer simulation techniques for exploring the detailed atomic structure and dynamic processes which occur at high temperature, and finally to consider the relationships between melt structure, thermodynamic properties and rheology within these liquids. These fundamental relations serve to bridge the extrapolation from often highly simplified melt compositions studied in the laboratory to the multicomponent systems found in nature. This volume focuses on the properties of simple model silicate systems, which are usually volatile-free. The behavior of natural magmas has been summarized in a previous Short Course volume (Nicholls and Russell, editors, 1990: Reviews in Mineralogy, Vol. 24), and the effect of volatiles on magmatic properties in yet another (Carroll and Holloway, editors, 1994: Vol. 30). In the chapters by Moynihan, by Webb and Dingwell, and by Richet and Bottinga, the concepts of relaxation and the glass transition are introduced, along with techniques for studying the rheology of silicate liquids, and theories for understanding the transport and relaxation behavior in terms of the structure and thermodynamic properties of the liquid. The chapter by Dingwell presents applications of relaxation-based studies of melts in the characterization of their properties. Chapters by Stebbins, by Brown, Farges and Calas, and by McMillan and Wolf present the principal techniques for studying the melt structure and atomic scale dynamics by a variety of spectroscopic and diffraction methods. Wolf and McMillan summarize our current understanding of the effects of pressure on silicate glass and melt structure. Chapters by Navrotsky and by Hess consider the thermodynamic properties and mixing relations in simple and multicomponent aluminosilicate melts, both from a fundamental structural point of view and empirical chemical models which can be conveniently extrapolated to natural systems. The chapter by Chakraborty describes the diffusivity of chemical species in silicate melts and glasses, and the chapter by Poole, McMillan and Wolf discusses the application of computer simulation methods to understanding the structure and dynamics of molten silicates. The emphasis in this volume is on reviewing the current state of knowledge of the structure, dynamics and physical properties of silicate melts, along with present capabilities for studying the molten state under conditions relevant to melting within the Earth, with the intention that these techniques and results can then be applied to understanding and modeling both the nature of silicate melts and the role of silicate melts in nature.

Description / Table of Contents: The scientific discoveries that have been made with noble gas geochemistry are of such a profound and fundamental nature that earth science textbooks should be full of examples. Surprisingly, this really is not so. The "first discoveries" include presolar components in our _ solar system, extinct radionuclides, primordial volatiles in the Earth, the degassing history of Mars, secular changes in the solar wind, reliable present day mantle degassing fluxes, the fluxes of extraterrestrial material to Earth, groundwater paleotemperatures and the ages of the oldest landscapes on Earth. Noble gas geochemistry has scored so many such "firsts" or "home runs" that it should permeate a lot of earth science thinking and teaching. Yet rather surprisingly it does not. Noble gas geochemistry also is a broader and more versatile field than almost any other area of geochemistry. It pervades cosmochemistry, Earth sciences, ocean sciences, climate studies and environmental sciences. Yet most modern Earth, planetary and environmental science departments do not consider noble gas geochemistry to be at the top of their list in terms of hiring priorities these days. Furthermore, with the exception of Ar geochronologists, noble gas geochemists are a surprisingly rare breed. Why is the above the case? Perhaps the reasons lie in the nature of the field itself. First, although noble gas geochemists work on big problems, the context of their data is often woefully under-constrained so that it becomes hard to make progress beyond the first order fundamental discoveries. Noble gas data are often difficult to interpret. Although some concepts are straightforward and striking in their immediate implications (e.g. mantle 3He in the oceans), others are to this day shrouded in lack of clarity. The simple reason for this is that in many situations it is only the noble gases that offer any real insights at all and the context of other constraints simply does not exist. Some examples of the big issues being addressed by noble gases are as follows and I have deliberately posed these as major unresolved questions that only exist because noble gas geochemistry has opened windows through which to view large-scale issues and processes that otherwise would be obscure. (1) Is the presolar noble gas component present in a tiny fraction of submicroscopic meteoritic C or is it ubiquitously distributed? (2) How did solar noble gases get incorporated into the Earth? (3) How did solar noble gases survive the protracted accretion of the Earth via giant impacts? (4) What is the origin of the noble gas pattern in the Earth's atmosphere? (5) Why are the Earth and Mars almost opposites in terms of the relative isotopic differences between atmosphere and mantle? (6) What is the Eresent source of Earth's primordial helium? Can we ignore the core? (7) What is the 2~e/ 2Ne of the mantle, how was it acquired and why is it different from the atmosphere? (8) How does one reconcile the stronlJ fractionation in terrestrial Xe with data for other noble gases? (9) How much radiogenic Ar should the Earth have? How well do we know KIU? (10) Are the light isotopes of Xe the same in the mantle and the atmosphere? If not, why not? (11) How are noble gases transported through the creeping solid earth? (12) How does one explain the heat - helium paradox? (13) How incompatible are the noble gases during melting? (14) How are atmospheric components incorporated into volcanic samples? (15) How are the excess air components incorporated into groundwater? (16) Why are continental noble gas paleotemperature records offset from oceanic temperature records? Noble gas data tell us that the Earth and solar system represent very complex environments. When we make our simple first order conclusions and models we are only at the tip of the iceberg of discoveries that are needed to arrive at a thorough understanding of the behavior of volatiles in the solar system. Who wants to hear that things are complicated? Who wants to hire in a field that will involve decades of data acquisition and analysis in order to sort out the solar system? Sadly, too few these days. This is the stuff of deep scientific giants and bold, technically difficult long-term research programs. It is not for those who prefer superficiality and quick, glamorous, slick answers. Noble gas geochemists work in many areas where progress is slow and difficult even though the issues are huge. This probably plays a part in the limited marketability of noble gas geochemistry to the nonspecialist. Second, noble gases is a technically difficult subject. That is, noble gas geochemists need to be adept 11t technique development and this has to include skills acquired through innovation in the lab. Nobody can learn this stuff merely with a book or practical guide. Reading Zen and the Art of Motorcycle Maintenance (by Robert Pirsig) would give you a clearer picture. This magnificent MSA-GS volume is going to be enormously useful but on its own it won't make anybody into a noble gas geochemist. Although the mass spectrometry principles are not complex, the tricks involved in getting better data are often self taught or passed on by working with individuals who themselves are pushing the boundaries further. Furthermore, much of the exciting new science is linked with technical developments that allow us to move beyond the current measurement capabilities. Be they better crushing devices, laser resonance time of flight, multiple collection or compressor sources - the technical issues are central to progress. Lastly, noble gas geochemists need a broad range of other skills in order to make progress. They have to be good at mass spectrometry as already stated. However, nowadays they also need to be able to understand fields as different as mantle geochemistry, stellar evolution, cosmochemistry, crustal fluids, oceanography and glaciology. They are kind of "Renaissance" individuals. Therefore, if you are thinking broadly about hiring scientists who love science and stand a good chance of making a major difference to our understanding of the solar system, earth and its environment - I would recommend you hire a really good noble gas geochemist. However, the results may take a while. If you want somebody who will crank out papers at high speed and quickly increase the publication numbers of your department then you may need to think about somebody else. The two are not mutually exclusive but think hard about what is really important. There was no short course associated with this volume, although an attempt was undertaken to get the volume printed in time for the V. M. Goldschmidt conference in Davos, Switzerland (mid-August 2002) at which there was a major symposium on noble gases.

Description / Table of Contents: This volume was prepared for a short course by the same title, organized by Russell J. Hemley and Ho-kwang Mao and sponsored by the Mineralogical Society of America, December 4-6, 1998 on the campus of the University of California at Davis. High-pressure mineralogy has historically been a vital part of the geosciences, but it is only in the last few years that the field has emerged as a distinct discipline as a result of extraordinary recent developments in high-pressure techniques. The domain of mineralogy is now no less than the whole Earth, from the deep crust to the inner core-the entire range of pressures and temperatures under which the planet's constituents were formed or now exist. The primary goal of this field is to determine the physical and chemical properties of materials that underlie and control the structural and thermal state, processes, and evolution of the planet. New techniques that have come 'online' within the last couple of years make it possible to determine such properties under extreme pressures and temperatures with an accuracy and precision that rival measurements under ambient conditions. These investigations of the behavior of minerals under extreme conditions link the scale of electrons and nuclei with global processes of the Earth and other planets in the solar system. It is in this broad sense that the term 'Ultrahigh-Pressure Mineralogy' is used for the title of this volume of Reviews in Mineralogy. This volume sets out to summarize, in a tutorial fashion, knowledge in this rapidly developing area of physical science, the tools for obtaining that knowledge, and the prospects for future research. The book, divided into three sections, begins with an overview (Chapter 1) of the remarkable advances in the ability to subject minerals-not only as pristine single-crystal samples but also complex, natural mineral assemblages-to extreme pressure-temperature conditions in the laboratory. These advances parallel the development of an arsenal of analytical methods for measuring mineral behavior under those conditions. This sets the stage for section two (Chapters 2-8) which focuses on high-pressure minerals in their geological setting as a function of depth. This top-down approach begins with what we know from direct sampling of high-pressure minerals and rocks brought to the surface to detailed geophysical observations of the vast interior. The third section (Chapters 9-19) presents the material fundamentals, starting from properties of a chemical nature, such as crystal chemistry, thermochemistry, element partitioning, and melting, and moving toward the domain of mineral physics such as melt properties, equations of state, elasticity, rheology, vibrational dynamics, bonding, electronic structure, and magnetism. The Review thus moves from the complexity of rocks to their mineral components and finally to fundamental properties arising directly from the play of electrons and nuclei. The following themes crosscut its chapters. Composition of the mantle and core Our knowledge of the composition of the Earth in part is rooted in information on cosmochemical abundances of the elements and observations from the geological record. But an additional and essential part of this enterprise is the utilization of the growing information supplied by mineral physics and chemistry in detailed comparison with geophysical (e.g. seismological) observations for the bulk of the planet. There is now detailed information from a variety of sources concerning crust-mantle interactions in subduction (Liou et aI., Chapter 2; Mysen et aI., Chapter 3). Petrological, geochemical, and isotope studies indicate a mantle having significant lateral variability (McDonough and Rudnick, Chapter 4). The extent of chemical homogeneity versus layering with depth in the mantle, a question as old as the recognition of the mantle itself, is a first-order issue that threads its way throughout the book. Agee (Chapter 5) analyzes competing models in terms of mineral physics, focusing on the origin of seismic discontinuities in the upper mantle. Bina (Chapter 6) examines the constraints for the lower mantle, with particular emphasis given to the variation of the density and bulk sound velocity with depth through to the core-mantle boundary region (Jeanloz and Williams, Chapter 7). Stixrude and Brown (Chapter 8) examine bounds on the composition of the core. Mineral elasticity and the link to seismology The advent of new techniques is raising questions of the mineralogy and composition of the deep Interior to a new level. As a result of recent advances in seismology, the depth-dependence of seismic velocities and acoustic discontinuities have been determined with high precision, lateral heterogeneities in the planet have been resolved, and directional anisotropy has been determined (Chapters 6 and 7). The first-order problem of constraining the composition and temperature as a function of depth alone is being redefined by high-resolution velocity determinations that define lateral chemical or thermal variations. As discussed by Liebermann and Li (Chapter 15), measurements of acoustic velocities can now be carried out simultaneously at pressures that are an order of magnitude higher, and at temperatures that are a factor of two higher, than those possible just a few years ago. The tools are in hand to extend such studies to related properties of silicate melts (Dingwell, Chapter 13). Remarkably, the solid inner core is elastically anisotropic (Chapter 8); with developments in computational methods, condensed-matter theory now provides robust and surprising predictions for this effect (Stixrude et aI., Chapter 19), and with very recent experimental advances, elasticity measurements of core material at core pressures can be performed directly (Chapters 1 and 15). Mantle dynamics The Earth is a dynamic planet: the rheological properties of minerals define the dynamic flow and texture of material within the Earth. Measurement of rheological properties at mantle pressures is a significant challenge that can now be addressed (Weidner, Chapter 16). Deviatoric stresses down to 0.1 GPa to pressures approaching 300 GPa can be quantified in high-pressure cells using synchrotron radiation (Chapter 1). The stress levels are an appropriate scale for understanding earthquake genesis, including the nature of earthquakes that occur at great depth in subducted slabs (deep-focus earthquakes) as these slabs travel through the Earth's mantle. Newly developed high-pressure, high-precision x-ray tools such as monochromatic radiation with modern detectors with short time resolution and employing long duration times are now possible with third-generation synchrotron sources to study the rheology of deep Earth materials under pressure (Chapter 1). Fate of subducting slabs One of the principal interactions between the Earth's interior and surface is subduction of lithosphere into the mantle, resulting in arc volcanoes, chemical heterogeneity in the mantle, as well as deep-focus earthquakes (Chapters 2 and 3). Among the key chemical processes associated with subduction is the role of water in the recycling process (Prewitt and Downs, Chapter 9), which at shallower levels is essential for understanding arc volcanism. Mass and energy transport processes govern global recycling of organic and inorganic materials, integration of these constituents in the Earth's interior, the evolution (chemically and physically) of descending slabs near convergent plate boundaries, and the fate of materials below and above the descending slab. Chapters 5 and 6 discuss the evidence for entrainment and passage of slabs through the 670 km discontinuity, and the possibility of remnant slabs in the anomalous D" region near the core-mantle boundary (Chapter 7). The ultimate fate of the materials cycled to such depths may affect interactions at the core-mantle boundary and may also hold clues to the initiation of diapiric rise. The evolution and fate of a subducting slab can now be addressed by experimental simulation of slab conditions, including in situ monitoring of a simulated slab in high-pressure apparatus in situ x-ray and spectroscopic techniques. The chemistry of volatiles changes appreciably under deep Earth conditions: they can be structurally bound under pressure (Prewitt and Downs, Chapter 9). Melting Understanding pressure-induced changes in viscosity and other physical properties of melts is crucial for chemical differentiation processes ranging from models of the magma ocean in the Earth's early history to the formation of magmatic ore deposits. (Chapter 13). Recent evidence suggests that melting may take place at great depth in the mantle. Seismic observations of a low-velocity zone and seismic anisotropy at the base of the mantle have given rise to debate about the existence of regions of partial melt deep in the mantle (Chapter 7). Deep melting is also important for mantle convection from subduction of the lithosphere to the rising of hot mantle plumes. Very recent advances in determination of melting relations of mantle and core materials with laser-heating techniques are beginning to provide accurate constraints (Shen and Heinz, Chapter 12). Sometimes lost in the debate on melting curves is the fact that a decade ago, there simply were no data for most Earth materials, only guesses and (at best) approximate models. Moreover, it is now possible to carry out in situ melting studies on multi-component systems, including natural assemblages, to deep mantle conditions. These results address whether or not partial melting is responsible for the observed seismic anomalies at the base of the mantle and provide constraints for mantle convection models (Chapter 7). The enigma of the Earth's core The composition, structure, formation, evolution, and current dynamic state of the Earth's core is an area of tremendous excitement (Chapter 8). The keys to understanding the available geophysical data are the material properties of liquid and crystalline iron under core conditions. New synchrotron-based methods and new developments in theory are being applied to determine all of the pertinent physical properties, and in conjunction with seismological and geodynamic data, to develop a full understanding of the core and its interactions with the mantle (Chapter 7). There has been considerable progress in determining the melting and phase relations of iron into the megabar range with new techniques (Chapter 12). Constraints are also obtained from theory (Chapter 19). These results feed into geophysical models for the outer and inner core flow, structural state, evolution, and the geodynamo. Moreover, there is remarkable evidence that the Earth's inner core rotates at a different rate than the rest of the Earth. This evidence in turn rests on the observation that the inner core is elastically anisotropic, a subject of current experimental and theoretical study from the standpoint of mineral physics, as described above. The thermodynamic framework Whole Earth processes must be grounded in accurate thermodynamic descriptions of phase equilibria in multi-component systems, as discussed by Navrotsky (Chapter 10). New developments in this area include increasingly accurate equations of state (Duffy and Wang, Chapter 14) required for modeling of phase equilibria as well as for direct comparison with seismic density profiles through the planet. Recent developments in in situ vibrational spectroscopy and theoretical models provide a means for independently testing available thermochemical data and a means for extending those data to high pressures and temperatures (Gillet et aI., Chapter 17). Accurate determinations of crystal structures provide a basis for understanding thermochemical trends (Chapter 9). Systematics for understanding solid-solution behavior and element partitioning are now available, at least to the uppermost regions of the lower mantle (Fei, Chapter 11). New measurements for dense hydrous phases are beginning to provide answers to fundamental questions regarding their stability of hydrous phases in the mantle (Chapters 3 and 9) and the partitioning of hydrogen and oxygen between the mantle and core (Chapter 8). Novel physical phenomena at ultrahigh pressures One of the key recent findings in high-pressure research is the remarkable effect of pressure on the chemistry of the elements, at conditions ranging from deep metamorphism of crustal minerals (Chapter 2) to "contact metamorphism" at the core-mantle boundary (Chapter 7). Pressure-induced changes in Earth materials represent forefront problems in condensed-matter physics. New crystal structures appear and the chemistry of volatiles changes (Chapter 9). Pressure-induced electronic transitions and magnetic collapse in transition metal ions strongly affect mineral properties and partitioning of major, minor, and trace elements (Chapter 11). Evidence for these transitions from experiment (Chapter 18) and theory (Chapter 19) is important for developing models for Earth formation and chemical differentiation. The conventional view of structurally and chemically complex minerals of the crust giving way to simple, close-packed structures of the deep mantle and a simple iron core is being replaced by a new chemical picture wherein dense silicates, oxides, and metals exhibit unusual electronic and magnetic properties and chemistry. In the end, this framework must dovetail with seismological observations indicating an interior of considerable regional variability, both radially and laterally depending on depth (e.g. Chapters 6 and 7). New classes of global models Information concerning the chemical and physical properties of Earth materials at high pressures and temperatures is being integrated with geophysical and geochemical data to create a more comprehensive global view of the state, processes, and history of the Earth. In particular, models of the Earth's interior are being developed that reflect the details contained in the seismic record but are bounded by laboratory information on the physics and chemistry of the constituent materials. Such "Reference Earth Models" includes the development of reference data sets and modeling codes. Tools that produce seismological profiles from hypothesized mineralogies (Chapters 4 and 5) are now possible, as are tools for testing these models against 'reference' seismological data sets (Chapter 6). These models incorporate the known properties of the Earth, such as crust and lithosphere structure, and thus have both an Earth-materials and seismological orientation. Other planets The Earth cannot be understood without considering the rest of the solar system. The terrestrial planets of our solar system share a common origin, and our understanding of the formation of the Earth is tied to our understanding of the formation of its terrestrial neighbors, particularly with respect to evaluating the roles of homogeneous and heterogeneous processes during accretion. As a result of recent developments in space exploration, as well as in the scope of future planetary missions, we have new geophysical and geochemical data for the other terrestrial planets. Models for the accretion history of the Earth can now be reevaluated in relation to this new data. Experiments on known Earth materials provide the thermodynamic data necessary to calculate the high-pressure mineralogy of model compositions for the interior of Mars and Venus. Notably, the outer planets have the same volatile components as the Earth, just different abundances. Studies of the outer planets provide both an additional perspective on our own planet as well as a vast area of opportunity for application of these newly developed experimental techniques (Chapter 1 and 17). New techniques in the geosciences The utility of synchrotron radiation techniques in mineralogy has exceeded the expectations of even the most optimistic. New spectroscopic methods developed for high-pressure mineralogy are now available for characterizing small samples from other types of experiments. For example, the same techniques developed for in situ studies at high pressures and temperatures are being used to investigate microscopic inclusions such as coesite in high-pressure metamorphic rocks (Chapter 2) and deep-mantle samples as inclusions in diamond (Chapter 3). With the availability of a new generation of synchrotron radiation sources (Chapter 1) and spectroscopic techniques (Chapter 17), a systematic application of new methods, including micro tomographic x-ray analysis of whole rock samples, is now becoming routinely possible. Contributions in technology. Finally, there are implications beyond the geosciences. Mineralogy has historically has led many to conceptual and technical developments used in other fields, including metallurgy and materials science, and the new area of ultrahigh pressure mineralogy continues this tradition. As pointed out in Chapter 1, many highpressure techniques have their origins in geoscience laboratories, and in many respects, geoscience leads development of high-pressure techniques in physics, chemistry, and materials science. New developments include the application of synthetic diamond for new classes of 'large-volume' high-pressure cells. Interestingly, information on diamond stability, including its metastable growth, feeds back directly on efforts to grow large diamonds for the next generation of such high-pressure devices (Chapter 1). Microanalytical techniques, such as micro-spectroscopy and x-ray diffraction, developed for high-pressure research are now used outside of this field of research as well. The study of minerals and mineral analogs under pressure is leading to new materials. As in the synthesis of diamond itself, these same scientific approaches promise the development of novel, technological materials.

Description / Table of Contents: Since the dawn of life on earth, organisms have played roles in mineral formation in processes broadly known as biomineralization. This biologically-mediated organization of aqueous ions into amorphous and crystalline materials results in materials that are as simple as adventitious precipitates or as complex as exquisitely fabricated structures that meet specialized functionalities. The purpose of this volume of Reviews in Mineralogy and Geochemistry is to provide students and professionals in the earth sciences with a review that focuses upon the various processes by which organisms direct the formation of minerals. Our framework of examining biominerals from the viewpoints of major mineralization strategies distinguishes this volume from most previous reviews. The review begins by introducing the reader to over-arching principles that are needed to investigate biomineralization phenomena and shows the current state of knowledge regarding the major approaches to mineralization that organisms have developed over the course of Earth history. By exploring the complexities that underlie the "synthesis" of biogenic materials, and therefore the basis for how compositions and structures of biominerals are mediated (or not), we believe this volume will be instrumental in propelling studies of biomineralization to a new level of research questions that are grounded in an understanding of the underlying biological phenomena.

Description / Table of Contents: Several years ago, John Rakovan and John Hughes (colleagues at Miami of Ohio), and later Matt Kohn (at South Carolina), separately proposed short courses on phosphate minerals to the Council of the Mineralogical Society of America (MSA). Council suggested that they join forces. Thus this volume, Phosphates: Geochemical, Geobiological, and Materials Importance, was organized. It was prepared in advance of a short course of the same title, sponsored by MSA and presented at Golden, Colorado, October 25-27. We are pleased to present this volume entitled Phosphates: Geochemical, Geobiological and Materials Importance. Phosphate minerals are an integral component of geological and biological systems. They are found in virtually all rocks, are the major structural component of vertebrates, and when dissolved are critical for biological activity. This volume represents the work of many authors whose research illustrates how the unique chemical and physical behavior of phosphate minerals permits a wide range of applications that encompasses phosphate mineralogy, petrology, biomineralization, geochronology, and materials science. While diverse, these fields are all linked structurally, crystal-chemically and geochemically. As geoscientists turn their attention to the intersection of the biological, geological, and material science realms, there is no group of compounds more germane than the phosphates. The chapters of this book are grouped into five topics: Mineralogy and Crystal Chemistry, Petrology, Biomineralization, Geochronology, and Materials Applications. In the first section, three chapters are devoted to mineralogical aspects of apatite, a phase with both inorganic and organic origins, the most abundant phosphate mineral on earth, and the main mineral phase in the human body. Monazite and xenotime are highlighted in a fourth chapter, which includes their potential use as solid-state radioactive waste repositories. The Mineralogy and Crystal Chemistry section concludes with a detailed examination of the crystal chemistry of 244 other naturally-occurring phosphate phases and a listing of an additional 126 minerals. In the Petrology section, three chapters detail the igneous, metamorphic, and sedimentary aspects of phosphate minerals. A fourth chapter provides a close look at analyzing phosphates for major, minor, and trace elements using the electron microprobe. A final chapter treats the global geochemical cycling of phosphate, a topic of intense, current geochemical interest. The Biomineralization section begins with a summary of the current state of research on bone, dentin and enamel phosphates, a topic that crosses disciplines that include mineralogical, medical, and dental research. The following two chapters treat the stable isotope and trace element compositions of modern and fossil biogenic phosphates, with applications to paleontology, paleoclimatology, and paleoecology. The Geochronology section focuses principally on apatite and monazite for U-ThPb, (U- Th)/He, and fission-track age determinations; it covers both classical geochronologic techniques as well as recent developments. The final section-Materials Applications-highlights how phosphate phases play key roles in fields such as optics, luminescence, medical engineering and prosthetics, and engineering of radionuclide repositories. These chapters provide a glimpse of the use of natural phases in engineering and biomedical applications and illustrate fruitful areas of future research in geochemical, geobiological and materials science. We hope all chapters in this volume encourage researchers to expand their work on all aspects of natural and synthetic phosphate compounds.