Brannerite

Formula:  (U,Ca,Y,Ce)(Ti,Fe)₂O₆

Origin of name:  For John Banner, American geologist

Crystal system:  Monoclinic

Crystal class:  2/m

Twinning:

Unit cell:

Colour:  Black, Brownish, green, yellowish brown or yellow

Diaphaneity:  Translucent to opaque

Luster:  Vitreous if fresh, resinous to dull

Habit:  Crystals indistinct; embedded grains and masses

Hardness:  4.5 to 5.5

Specific gravity:  4.2 to 5.4

Cleavage:  None

Tenacity:

Streak:  Dark greenish brown to yellow

Synonyms/varieties:

Comments:  Series with thorutite; dimorphous with orthobrannerite