Review of the terminology used in the public exhibition of Spanish minerals at the Museum of Geomining (Geological Survey of Spain, Madrid)

The terms used to identify minerals in public exhibitions usually depends primarily upon the textural, chemical and/or structural problems related to their classification. Furthermore, the label attached to any specimen can only contain a limited amount of information, thus limiting still more the specimen's complete identification. We have examined this problem with the intention of achieving greater rigour in mineral classification whilst at the same time providing the public with the most complete information possible. Five recurring problems encountered in the permanent collections of the Spanish Museum of Geomining in Madrid have been dealt with (allowing the reader to become a virtual visitor): a) specimens made up of several species; b) specimens composed of minerals that form solid-solutions; c) mixed materials of low crystallinity; d) specimens with chemical or structural zones; and e) specimens showing evidence of pseudomorphosis. The minerals involved are common and come from sites in Spain of interest to museums, collectors or commercial ventures. We have only undertaken analyses, using X-ray diffraction, when the information available is non-existent or insufficient. The suggestions made and decisions adopted may help in the labelling of other collections both public and private. (Author) 60 refs.