ALBERT

Description / Table of Contents: Mineralogy and Geology of Natural Zeolites was published in 1977. Dr. Fred Mumpton, a leader of the natural zeolite community for more than three decades, edited the original volume. Since the time of the original MSA zeolite short course in November 1977, there have been major developments concerning almost all aspects of natural zeolites. There has been an explosion in our knowledge of the crystal chemistry and structures of natural zeolites (Chapters 1 and 2), due in part to the now-common Rietveld method that allows treatment of powder diffraction data. Studies on the geochemistry of natural zeolites have also greatly increased, partly as a result of the interests related to the disposal of radioactive wastes, and Chapters 3, 4, 5, 13, and 14 detail the latest results in this important area. Until the latter part of the 20th century, zeolites were often looked upon as a geological curiosity, but they are now known to be widespread throughout the world in sedimentary and igneous deposits and in soils (Chapters 6-12). Likewise, borrowing from new knowledge gained from studies of synthetic zeolites and properties of natural zeolites, the application of natural zeolites has greatly expanded since the first zeolite volume. Chapter 15 details the use of natural zeolites for removal of ammonium ions, heavy metals, radioactive cations, and organic molecules from natural waters, wastewaters, and soils. Similarly, Chapter 16 describes the use of natural zeolites as building blocks and cements in the building industry, Chapter 17 outlines their use in solar energy storage, heating, and cooling applications, and Chapter 18 describes their use in a variety of agricultural applications, including as soil conditioners, slow-release fertilizers, soil-less substrates, carriers for insecticides and pesticides, and remediation agents in contaminated soils. Most of the material in this volume is entirely new, and Natural Zeolites: Occurrence, Properties, Applications presents a fresh and expanded look at many of the subjects contained in Volume 4. It is our hope that this new, expanded volume will rekindle interest in this fascinating and technologically important group of minerals, in part through the 'Suggestions for Further Research' section in each chapter.

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: This volume was prepared in conjunction with a short course, "Nanoparticles in the Environment and Technology," convened on the campus of the University of California, Davis, CA on December 8 and 9, 2001. Over the years, volumes in this series have taken a variety of forms. Many have focused on mature fields of investigation to draw together a comprehensive body of work and provide a definitive, up to date reference. A few, however, have sought to provide enough coverage of an emerging or re-emerging field to allow the reader to identify important and exciting gaps in current knowledge and opportunities for new research. This volume falls into the later category. Our primary goal in convening the short course and assembling this text is to invigorate future research. Early Reviews in Mineralogy dealt with specific groups of minerals, one (or two) volumes at a time. In contrast, this volume deals explicitly with the topic of crystal size in many different systems. Until recently, the special and complicated nature of the very smallest particles rendered them nearly impossible to study by conventional methods. Even today, the challenges associated with evaluating the size-dependence of a mineral's bulk and surface structures, properties, and reactivity are significant. However, ongoing improvements in sophisticated characterization, theory, and data analysis make particles previously described (often inaccurately) as "amorphous" (or even more mysteriously as "X-ray amorphous") amenable to quantitative evaluation. Thermochemical, crystal chemical, and computational chemical approaches must be combined to understand particles with diameters of 1 to 100 nanometers. Determination of the variation of structure, properties, and reaction kinetics with crystal size requires careful synthesis of size- and perhaps morphology-specific samples. These problems demand integration of mineralogical and geochemical approaches. Thus, it is appropriate that the current issue belongs to the era of Reviews in Mineralogy and Geochemistry. Nanoparticles and the Environment targets naturally occurring, finely particulate minerals, many of which form at low temperature. Thus, many of the compounds of interest are those of the "clay fraction". Of course, there have been decades of critical work on the structures, microstructures, and reactivity of finely crystalline or amorphous minerals, especially oxides, oxyhydroxides, hydroxides, and clays. We will not summarize what is known in general about these (for this, the reader is referred to earlier Reviews in Mineralogy volumes). Rather, our goal is to focus on the features of these materials that stem directly or indirectly from their size. The term "nanoparticles" is much more than a re-labeling designed to align "clay" (sized) minerals with nanotechnology and its goals. The term signifies that the substance has physical dimensions that are small enough to ensure that the structure and/or properties and/or reactivity are measurably particle size dependent, yet the particle is large enough to warrant its distinction from aqueous ions, complexes, or clusters. The chemistry, physics, and geology of particles at this intermediate scale are unique, fascinating, and important. Of particular interest are those properties that emerge only after a cluster of atoms has grown beyond some specific size, and disappear once the particle passes out of the "nanoparticle" size regime. There are some compelling examples of size-dependent phenomena. It is well known that the melting temperature of nanocrystals (defined as crystals having properties intermediate between molecular and crystalline) decreases dramatically as the radius of the cluster decreases. Absorption and luminescence spectra for small crystals are determined by the quantum-size effect. Decreasing nanocrystal size correlates with increased total energy of band edge optical transitions. As a consequence, the color of some nanocrystals correlates strongly with their particle size. Current world-wide interest in "nanotechnology" and "nanomaterials" offers a unique opportunity for the Earth sciences. Both the level of visibility and the explosion of synthesis and characterization techniques in physics, chemistry, and materials science provide mineralogy and geochemistry with new opportunities. It is important for us to show that the "nano" field consists of more than micromachines and electronic devices, and that nanoscale phenomena permeate and often control natural processes. Why all the fuss about nanoparticles now? As increasing attention in engineering is focused on making smaller and smaller machines, questions about the fundamental processes that govern nanoparticle form, stability, and reactivity emerge. The geoscience community is well equipped to tackle the basic science concepts associated with these questions. However, we have our own reasons to study size-dependent phenomena. Size-dependent structure and properties of Earth materials impact the geological processes they participate in. This topic has not been fully explored to date. Chapters in this volume contain descriptions of the inorganic and biological processes by which nanoparticles form, information about the distribution of nanoparticles in the atmosphere, aqueous environments, and soils, discussion of the impact of size on nanoparticle structure, thermodynamics, and reaction kinetics, consideration of the nature of the smallest nanoparticles and molecular clusters, pathways for crystal growth and colloid formation, analysis of the size-dependence of phase stability and magnetic properties, and descriptions of methods for the study of nanoparticles. These questions are explored through both theoretical and experimental approaches. Nanoparticles participate in every crystallization reaction and they constitute a major source of surface area in environments where virtually every important reaction takes place on a surface. They are components of enzymes and key biomolecules and their presence may record the early existence of life. How can we not be fascinated by these remarkable, and special, forms of matter?