Pleochroism moderate yellow to dark green in stones that are transparent 2V angle 78–82° calc 84–73° meas Dispersion r lt v Ultraviolet fluorescence inert Absorption spectra faint line at 503 nm References Actinolite is an amphibole silicate mineral with the chemical formula and iron rich ferro actinolite ☐Ca2 Mg2 5 0 0Fe2 2 5 5 0 Si8O22 OH 2