gems, fluorite, inclusions in fluorite, fluid inclusions

The casual discovery of a fluorite mineralization in Mesozoic limestones of northwestern Sicily has suggested a geochemico-petrographic investigation of its possible origin. The fluorite has been found associated with calcite, barite, quartz and iron oxides and is present in varieties of five different colours. The petrographic study, after outlining the features of the host-rock, shows the textural relationships between the mineral and its associated phases. The geochemical behaviour of Mg, Mn, Fe and Sr is more clearly identified among the minor elements determined in the fluorites, and in the limestones associated with fluorite and even in the non-mineralized limestones. REE distribution patterns strongly emphasize the hydrothermal origin of the fluorite mineralization. Most of the fluorite samples indicate that the solution from which it crystallized interacted with the limestone. Fluorite and calcite did not crystallize from the same solution.