Marialite

Formula:  Na₄Al₃Si₉O₂₄Cl

Origin of name:  For Maria vom Rath, wife of German mineralogist

Crystal system:  Tetragonal

Crystal class:  4/m

Twinning: 

Unit cell: a = 12.06 Å, c = 7.59 Å

Colour:  Colourless, white, gray, bluish, greenish, pink, yellowish, violet, brown

Diaphaneity: 

Luster:  Vitreous to pearly or resinous

Habit: 

Hardness:  5.5 to 6

Specific gravity:  2.50 to 2.62

Cleavage:  2; {100} and {110} distinct

Tenacity: 

Streak: 

Synonyms/varieties:

Comments:  Series with meionite, end member of scapolite series