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!
Occurred in a Mississippi Valley-like deposit within the Franklin marble associated with baryte, fluorite, dolomite, pyrite. Some masses of oil-green spahalerite were transparent and faceting grade material.
Lime Crest Quarry, Sparta Township, Sussex County, New Jersey, USA