[ Top ] [ Japanese ]

Polycrase-(Y)

Year of discovery: 1870 (Rasvåg quarries, Norway), 1954 (Japan)

Locality list: 8 localities of polycrase-(Y)

• (Y,U)(Ti,Nb)₂O₆
• (Y,U,Ca,Ce,U,Th)(Ti,Nb,Ta)₂O₆
• [(Y³⁺,U⁵⁺)][(Ti⁴⁺,Nb⁵⁺)₂O₆]

• Class: Polycrase group
• Class: Dititanate
• Radioactive: Strong

• Y => U: Uranopolycrase

• Ti => Nb: Euxenite-(Y) (Series)
• Ti => Ta: Tanteuxenite-(Y)

• O => (O,OH): Aeschynite-(Y), Yttrocrasite-(Y)

• Color: Black, Brown
• Streak: Yellowish brown
• Luster: Vitreous
• Diaphaneity: Opaque

• Cleavage: No
• Hardness: 5-6
• Density: 5.0

• System: Amorphous, Orthorhombic (Morphology)
• Group: mmm, Pcan
• Lattice: a=5.6, b=14.6, c=5.2