Originally a mixture of 25% Nontronite and 75% Opal-Cristobalite from Meenser Steinberg, Göttingen, Lower Saxony, Germany. Frequently used for a bright green nontronite of varying purity.
(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.