1. ⠠ ⠠ , -. Ni, Fe, Co, Pt, Pd, Ru, Os, Ir, Re, Cr, Mn . , . , , - , . , , 0,5-1 . ( 6 ), , ( The Gemmologist, v. 30, 356 1961). 1970 . . . (Liddicoat, 1970) , X