Riebeckite and Bastnaesite-(Ce)
Zagi Mountain, Khyber Pakhtunkhwa, Pakistan
Small Cabinet, 5.5 x 4.0 x 2.5 cm
Ex. Herb Obodda
A superb group of lustrous black crystals of this very rare species, to 3.3 cm, perched on a granite matrix. A small reddish-brown Bastanite xl is nestled amidst the group. Although Riebeckite is a common black rock-forming mineral at the deposit, it is very uncommon as crystallized specimens. According to Dr. Peter Leaven's analysis (University of Delaware) "An analyzed grain is close to pure Riebeckite but has some K and Ca as well as NA, and minor MN and MG substituting for FE, as well as trace AL, probably substituting for Si." This specimen is pictured in an article on Zagi Mountain by Dr. Peter Leavens and Obodda, published in the "Rare Earths" issue of The Mineralogical Record, May-June 2004 (Volume 35, number 3): figure 25 on page 218. This specimen was in many Obodda exhibit cases over the years.