Aliettite

Formula:  Ca_0.2Mg₆(Si, Al)₈O₂₀(OH)₄^.4H₂O

Origin of name:  For Andrea Alietti (1923- ), Italian  clay mineralogist of the University of Modena, Modena, Italy, who first studied the structure of this mineral

Crystal system:  Hexagonal

Crystal class:  Unknown

Twinning:

Unit cell: a = 5.216 Å, c = 24.6 Å

Colour:  Colourless, pale yellow or pale green

Diaphaneity: Translucent

Luster: Earthy, dull

Habit:  Irregular, tabular to platy, microscopic crystals

Hardness:  1

Specific gravity: 

Cleavage: 1; perfect 

Tenacity:

Streak: White

Synonyms/varieties:

Comments:  a 1:1 regularly interstratified talc-trioctahedral smectite. Formed as an alteration product in serpentinised ophiolites and residual in soils derived there from, also in altered dolostones