This is a compilation of bibliographic (historical and descriptive) information for the minerals first described from Brazil; it includes both valid and invalid, discredited species, unnamed, unidentified, problematic minerals, and so on. This work brings together as much data as possible concerning type mineral species. It will save future researchers a lot of work because it contains data from many publications that are difficult to obtain.

"Brazil was the leading world producer of gold and of diamonds between the mid-18th century and the mid-19th century. At the present time, it is the leading world producer of iron ore, tin and niobium, and an important producer of manganese, aluminium, silicon, tantalum, rare earths, graphite, magnesite and countless other ores.....Brazil is the leading world producer of tourmaline (of all colors), of quartz (colorless, rutilated, amethyst and agate), of beryl (aquamarine, morganite and heliodore, and the second ranking world producer of emerald), of topaz (imperial, blue and colorless), alexandrite, euclase, phenakite and many others" INTRODUCTION.

An integrated reference on the economic geology of titanium that covers all the basic processes of formation of titanium-mineral deposits, organized along the lines of a geochemical cycle of titanium in order to facilitate the description of linkages among deposit types. Annotation copyright Book Ne

As the importance and dependence of specific mineral commodities increase, so does concern about their supply. The United States is currently 100 percent reliant on foreign sources for 20 mineral commodities and imports the majority of its supply of more than 50 mineral commodities. Mineral commodities that have important uses and face potential supply disruption are critical to American economic and national security. However, a mineral commodity's importance and the nature of its supply chain can change with time; a mineral commodity that may not have been considered critical 25 years ago may be critical today, and one considered critical today may not be so in the future. The U.S. Geological Survey has produced this volume to describe a select group of mineral commodities currently critical to our economy and security. For each mineral commodity covered, the authors provide a comprehensive look at (1) the commodity's use; (2) the geology and global distribution of the mineral deposit types that account for the present and possible future supply of the commodity; (3) the current status of production, reserves, and resources in the United States and globally; and (4) environmental considerations related to the commodity's production from different types of mineral deposits. The volume describes U.S. critical mineral resources in a global context, for no country can be self-sufficient for all its mineral commodity needs, and the United States will always rely on global mineral commodity supply chains. This volume provides the scientific understanding of critical mineral resources required for informed decisionmaking by those responsible for ensuring that the United States has a secure and sustainable supply of mineral commodities.

Each gem deposit-whether of primary origin in the parent rocks; or secondary as alluvial placers in valley floors, river gravels, or the sand of oceanic shelves presents an eloquent chronicle of the Earth's life story. It reveals to the expert the prodigious processes which formed the present crust of our planet, of which this volume discloses a small but exciting detail. The materials of the Earth's crust are the rocks. In this book, the author expounds on how they were formed, why they altered, why they became the cradles of precious gemstones, how they are categorized, and how they are now exploited by man. What initiates the growth of gemstones? How do they crystallize? Why do gemstones of the same species, originating from different sources, vary? What causes the occurrence of varieties? Why do diamonds, unlike other precious stones, occur not near the Earth's surface in its crust, but deep down beneath it in the upper mantle? These are only a few of the entrancing subjects discussed in this enlightening volume. The reader learns that the Earth is surprisingly alive and altering constantly-sometimes through slow and equable changes and at times by violent and tremendous cataclysms, events from which gemstones issue.