This is a unique mixed-mineral specimen, that due to its manganocalcite content, is of interest as a fluorescent specimen. It consists of white to light pink nodular growths of small intergrown scalenohedral crystals of manganocalcite on a bed of pyrite and large tetrahedrite crystals, with small clusters of quartz crystals. It is from the Huaron mine, Pasco department, Peru. The manganocalcite shows an orange/red fluorescent response under all UV wavelengths, brighest under mid wave. This specimen measures 8.1 x 6.5 x 3.0 cm, and weighs 206 grams. Manganocalcite is a variety of calcite in which manganese replaces some of the calcium in the crystal structure, and imparts the property of beautiful orange to pink fluorescence under UV.
