The mineralogy of Leicestershire.

The mineralogical bibliography of Leicestershire, up to July, 1972, has been examined and critical analyses have been made of its 1375 references. The 134 mineral species recognized as indigenous to the county have been examined both physically and in relation to their individual geological environments. The physical examination has included X-ray diffraction techniques, qualitative and quantitative analysis. As a result certain species, formerly regarded as indigenous, have been discredited. 65 species have been erected as new county records and 5 new to British records. The geological environments of the minerals have been examined, one section of the work taking the form of an outline of the geology, another, the final section, examining the minerals in their genetic relationship to the geology. Although currently conceded that the allocation of mineral associations to set ''types" of ore genesis is no longer acceptable, an attempt has been made to allocate those found in Leicestershire to the set "types" as described by Park and MacDiarmid (1970) as follows:;1. Pegmatites.;2. Hypothermal deposits.;3. Mesothermal deposits.;4. Epithermal deposits.;5. Telethermal deposits.;6. Syngenetic deposits.;7. Supergene effects.;Rock forming minerals have only been examined where such species have been found in euhedral development, and they are not described as inherent components of rocks. Where problematical phenomena have been encountered during the course of the work, e.g. the anomalous fluorescence of chalcocite under short wave ultraviolet light, hypotheses have been erected to account for them. Each species has been examined in the order set out by Hey (1962) in his Chemical Index of Minerals, and the descriptive mineralogy has been divided into 12 sections: I The Elements II The Sulphides III The Oxides IV The Halides V The Carbonates VI The Nitrates VII The Silicates VIII The Phosphates IX The Vanadates X The Sulphates XI The Molybdates and Tungstates XII The Hydrocarbon Compounds.