Die Strukturforschung der Festkörper hat mit Beobachtungen an Mineralien begonnen, sie hat sich als ein Spezialgebiet der Physik, Physikalischen Chemie und Mineralogie zu großer Bedeutung entwickelt und wird im vorliegenden Werk mit ihren Ergebnissen auf die Ausgangsstoffe, d. h. die in der Natur auftretenden Kristallarten, die Mineralien, angewandt, mit dem Ziel, unter Beachtung der chemischen und strukturellen Verwandtschaftsbeziehungen eine „möglichst natürliche Klassifikation der Mineralien" zu entwickeln.

The purpose of the present text is to provide a concise survey of the history of mineralogy and crystallography through the year 1919. Hopefully, it reflects this rich area of study showing the development of these important scientific endeavors from simple origins through a maturity, which today some might regard as no more than technical art. This is mirrored in the fact that few people now would claim mineralogy as a science balanced on the edge of significant discovery, but that was not the case in the past. Then, mineralogy and its companion study crystallography, were important investigations with each new discovery being widely publicized and debated. Many researchers, some of whom may be counted among the greatest geniuses of the human race, explored, contemplated, and wrote about minerals and crystals. This history tries in some measure to spotlight these people and their discoveries. It is also written as a companion work to Mineralogy and Crystallography: A Biobibliography, which fully describes many of the books relevant to these studies across the same time period <...>

The word mineral means different things to different people. In ancient times, people divided all things on Earth into the animal, vegetable, or mineral kingdoms, so a mineral was any natural inorganic substance. Today, dieticians use the term to refer to nutritional elements such as calcium, iron, or sodium, while miners often use it for anything they can take out of the ground—including coal, sand, or gravel. Mineralogists and geologists of the twentieth century developed a more specific definition: Minerals are chemical compounds that are normally crystalline and form by geological processes. They must also have a well-defined chemical composition.

Mineralogical studies of platinum-group minerals (PGM) made during the period 1970-1995 are compiled in this paper for PGM obtained from platinum- and gold-bearing placer deposits of fifteen countries. A total of 3399 quantitative electron microprobe analyses of 37 different PGM are presented, together with analytical data plotted on compositional diagrams. The data reflect the dominance of Pt-Fe alloys (1723 analyses) and Os-Ir-Ru-Pt alloys (976 analyses) in the placers. The platinum-group element (PGE) alloys, as well as some other PGM, generally occur as grains less than one millimetre in size.