Occurs as warty (veruginous) olive-green, vitreous masses associated with thulite and other species in cavities in a granitic pegmatite of the Wissahickon formation. Possibly a magnesian Chamosite or Zoisite
(TL) indicates type locality. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.