Wollastonite in Calcite in White Light, Parker Shaft, Franklin, New Jersey
Wollastonite is a calcium inosilicate mineral (CaSiO3) that may contain small amounts of iron, magnesium, and manganese substituting for calcium. It is usually white. It forms when impure limestone or dolostone is subjected to high temperature and pressure sometimes in the presence of silica-bearing fluids as in skarns or contact metamorphic rocks. Associated minerals include garnets, vesuvianite, diopside, tremolite, epidote, plagioclase feldspar, pyroxene and calcite. Wollastonite from Franklin and Sterling Hill occurs as white rock-locked idiomorphic crystals, varying in size up to 7 cm; the luster is vitreous, and the cleavages are perfect, resulting in splintery breakage. Local material has not been examined optically. The fluorescence in ultraviolet varies in both hue and intensity, perhaps due to Mn content. In general, the fluorescence is strong in shortwave and weak in longwave. The best Franklin specimens fluoresce with a vivid orange color and occur in assemblages (calcite, willemite, hardystonite) which provide spectacular fluorescent specimens. Sterling Hill wollastonite occurs in idiomorphic crystals, and thus also provides very esthetic fluorescent specimens; the fluorescent color varies substantially, from orange to light yellow. Wollastonite is sometimes visually confused with pectolite or prehnite, both of which can be white and fibrous. Fluorescence is a luminescence that is mostly found as an optical phenomenon in cold bodies, in which the molecular absorption of a photon triggers the emission of a photon with a longer (less energetic) wavelength. The energy difference between the absorbed and emitted photons ends up as molecular rotations, vibrations or heat. Sometimes the absorbed photon is in the ultraviolet range, and the emitted light is in the visible range, but this depends on the absorbance curve and Stokes shift of the particular fluorophore.
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Keywords: calcite, collecting, crystal, crystals, display, fluorescence, fluorescent, fluorescing, franklin, geology, hunting, identification, jersey, lamps, light, lighting, longwave, mineral, minerals, mines, nj, parker, phosphorescence, shaft, shortwave, shows, specimen, specimens, ultraviolet, uv, white, wollastonite
