Calcite–Fluorite cluster, Mekhtar (54 g)

Description

This hand-sized cluster combines translucent to transparent pale yellow and clear calcite with clear to faint grey fluorite crystals sitting on a darker brownish granular base. Several blocky to tabular-looking crystals show sparkling faces with minor dark speckling on some faces; brownish granular material occupies the centre and rear of the piece. The specimen measures 6 × 6 × 2.5 cm and weighs 54 g. Crystals are generally blocky to tabular in habit and display clear to pale yellow tones alongside faint grey areas; is noted in the supplied description. The brown granular material forms the base and fills parts of the cluster. Fluorite is calcium fluoride (CaF2) and calcite is calcium carbonate (CaCO3); both commonly occur together in a range of hydrothermal and sedimentary settings. This example is from Mekhtar, Loralai District, Balochistan, Pakistan, and shows the mixed calcite–fluorite character typical of such associations.