Atencioite

Formula: Ca₂Fe²⁺Mg₂Fe²⁺₂Be₄[(OH)₄|(PO₄)₆] · 6H₂O

Origin of name: The name is for Dr. Daniel Atencio, professor of mineralogy at the Geoscience Institute of the University of São Paulo, Brazil.

Crystal system: Triclinic

Crystal class: -1

Twinning: 

Unit cell: a = 6.668, b = 9.879, c = 9.883

Colour: Greenish brown

Diaphaneity: Transparent

Luster: Vitreous

Habit: sub-parallel induviduals and spherules

Hardness: 4.5

Specific gravity: 2.84

Cleavage: None

Tenacity: Brittle

Streak: White

Synonyms/varieties:

Comments:  Member of the roscherite group