Tantalaeschynite-(Y)

General Information: Chemical Formula:(Y,Ce,Ca)(Ta,Ti,Nb)2O6 Composition:(Molecular Weight = 499.75 gm)Calcium 0.80 % CaCerium 8.41 % CeYttrium 10.67 % Y Tantalum 54.31 % TaTitanium 2.87 % TiNiobium 3.72 % NbOxygen 19.21 % O  Empirical Formula: (Y)0.6Ce0.3Ca0.1Ta1.5Ti0.3Nb0.2O6 IMA Status:Approved IMA 1987 Name Origin:Named for its composition and from the Greek for "shame," in allusion to the inability of chemists, at the time of its discovery, to separate some of its constituents.Physical Properties: Cleavage:None Color:brownish black or black. Density:6.39 Diaphaniety:Subtranslucent Hardness:5.5-6 - Knife Blade-Orthoclase Luster:Adamantine Streak:yellowish brownMore details...