548 Crystallography

Dana Classification

"The Dana System of Mineralogy was first published in 1837 by James Dwight Dana, a leading geologist of his time; it is in its eighth edition (1997 ed.). The Dana classification, assigns a four-part number to a mineral species. First is its class, based on important compositional groups; next, the type gives the ratio of cations to anions in the mineral; finally, the last two numbers group minerals by structural similarity with a given type or class."

SnowTerm Thesaurus

"The project purpose is to develop and maintain a reference structured terminology in the domain of the cryosphere environment. The identification of the potential sources of terminology was carried out with the assistance of experts of the Arabba Avalanche Centre. The result consists of a certain number of lists of terms, usually contained in glossaries where they are supplied with one or more definitions and scarcely organised within a structure. In certain cases they are clustered in thematic areas. The terms of these lists were selected according to their pertinence and relevance.

International Classification for Seasonal Snow on the Ground

"Since 1990 our collective knowledge of snow and the techniques we use to observe its characteristics have evolved. Thus, in 2003, the current classification (Colbeck et al., 1990) needed an update, but the users of the 1990 classification felt that corrections and additions should be kept to a minimum. Following the spirit of the previous editions, the Working Group on Snow Classification took care to again provide a concise document usable by user groups of quite different specialties: snow scientists, practitioners, scientists from other fields, as well as interested lay persons.