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!
Hundreds of crystals in some pockets, often "piercing" smoky quartz. Flawless crystals are rare; usually fractured. Large pocket crystals vary but are usually striated to silky, slender and elongated, from small needles up to 30 cm, but typically a few cm long. Color zoning is usually longitudinal, short and terminal in shades of green, pink, golden yellow and blue with up to 5 colors. Antilogous poles typically pale green, yellow, pink; analogous poles usually colorless, pale green, aqua. w/thin indigo cap, or sometimes with a narrow pale colored zone immediately beneath and parallel to the pedion. Tiny crystals may be any color throughout. Concentric “watermelon” zoning is not common. Some fragments of green prisms are overgrown by later pink zones. Also found frozen in matrix with beryl, fluorapatite, fluorite, muscovite, smoky quartz, lepidolite, microlite, columbite.
Habit:
Elongated trigonal prisms, antilogous pole terminated with rhombohedral pyramids {1bar11}, analgous pole dominated by a pedion.
Gillette Quarry, Haddam Neck, Haddam, Middlesex County, Connecticut, USA