Vote for your favorite mineral in #MinCup26! - Sphalerite vs. Anorthite Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
The following data on a yellow transparent crystal is provided by Chukanov (2014): Empirical formula is (electron microprobe) (Mg5.5Fe1.5)(SiO4)3F1.4(OH)0.6. Wavenumbers (cm-1): 3560, 3430sh, 990s, 956s, 888s, 848, 760, 750, 614, 540, 488s, 440sh,404s, 390sh
San Vito Quarry, San Vito, Ercolano, Metropolitan City of Naples, Campania, Italy