Tienshanite

Tienshanite, named for the Tian Shan Range in Mongolia, is a rare borosilicate mineral, though rock-forming in some parts of its original locality at the Dara-i-Pioz Glacier in Tajikistan. Its formula is extremely complex: KNa₃(Na,K,[])6(Ca,Y,RE)₂Ba₆(Mn,Fe,Zn,Ti)₆(Ti,Nb)₆Si₃₆B₁₂O₁₁₄[O_5.5(OH,F)_3.5]F₂.