AM_Tumchaite Formula: (Zr.8 Sn.2) Si4 Na2 O13 H4 Name: Tumchaite Unit cell: 9.144 8.818 7.537 90.0 113.22 90.0 , V=558.49 Space group: P121/C1 (14)

Subbotin V V , Merlino S , Pushcharovsky D Y , Pakhomovsky Y A , Ferro O , Bogdanova A N , Voloshin A V , Sorokhtina N V , Zubkova N V , American Mineralogist , 85 (2000) p.1516-1520, Tumchaite Na2(Zr,Sn)Si4O11.2H2O - a new mineral from carbonatites of the, Vuoriyarvi alkali-ultrabasic massif, Murmansk Region, Russia