Ferberite

Field of view: 100 mm. Ferberite associated with löllingite. The tabular black crystal at the center is ferberite. The surrounding massive silver-white parts with a metallic luster are löllingite exhibiting weak cleavage. The white parts with a vitreous luster in the interstices of löllingite are quartz.

Recovered from a löllingite vein in a pneumatolytic deposit formed near the boundary between welded tuff and S-type (Ilmenite-series) granite, members of a caldera complex. Formed in the Late Cretaceous (70 Ma).

Ferberite from this location was described in 1972.