Kulkeite

Formula:  Na_0.35Mg₈Al(AlSi₇)O₂₀(OH)₁₀

Origin of name:  For Holgar Kulke, German mineralogist

Crystal system:  Monoclinic

Crystal class:  Unknown

Twinning: 

Unit cell: 

Colour:  Colourless

Diaphaneity:  Transparent

Luster:  Pearly on cleavage

Habit:  Crystals, platy to subhedral to 2mm, aggregates

Hardness:  2

Specific gravity:  2.70

Cleavage:  1; {001} perfect

Tenacity: 

Streak:  White

Synonyms/varieties:

Comments:  A 1:1 regular interstratification of talc and trioctahedral chlorite