Frankamenite

Formula:  K₃Na₃Ca₅(Si₁₂O₃₀)F₃(OH) ^. H₂O

Origin of name:  For Viktor Frank-Kamenetskii, Russian mineralogist

Crystal system:  Triclinic

Crystal class:  1

Twinning:

Unit cell:

Colour:  Greyish lilac, bluish gray; light green

Diaphaneity:

Luster:  Vitreous

Habit:  Laths around 1 cm long, up to 15 cm long

Hardness:

Specific gravity:

Cleavage:  2; {010} and {100} perfect

Tenacity:

Streak:  White

Synonyms/varieties:

Comments:  Dimorphous with canasite; hardness and density similar to canasite