gems, corundum, chemistry.2, crystallography

This volume offers a comprehensive crystallogenetic overview on the morphology of minerals based on the authors' original ideas. Theories of crystal growth are briefly dealt with, attenetion being paid to the classical layer-by-layer and dislocation mechanisms. The modification of crystal forms of the most important rock-forming and ore-forming minerals, presented by their principal crystal habits, is checked by both observation in their natural occurences and laboratory experiments. Crystal growth by accretion of clusters and/or submicroscopic crystallites under specific natural environments is also discussed. The examples used illustrate crystallization and variation in the crystal habits of minerals in magnetic, pegmatitic, hydrothermal, weathering, sedimentary and metamorphic environments. The trends of crystal habit variation have been used for genetic interpretations and for outlining corresponding morphological zonalities.