Arsenoflorencite

Formula:  (Ce, La, Nd) Al₃(AsO₄, PO₄)₂(OH)₆

Origin of name:  From arsenic and relation to florencite

Crystal system:  Hexagonal

Crystal class:  -3 2/m

Twinning:

Unit cell: a = 7.029 Å, c = 16.517 Å

Colour:  Creamy white, colourless, tan

Diaphaneity: Translucent

Luster: Vitreous

Habit:  Euhedral to subhedral scalenohedral crystals and fragments 0.1-0.5 mm across

Hardness:  3.5

Specific gravity:  4.096

Cleavage: None

Tenacity: Brittle

Streak: White

Synonyms/varieties:

Comments:  Three distinct species with the extensions -(Ce), -(Nd) and -(La) indicating the predominant rare earth cation in the formula. Member of the crandallite group. Found as detrital grains in heavy mineral concentrates.