Chiolite

Formula:  Na₅ Al₃ F₁₄

Origin of name:  From Greek for snow

Crystal system:  Tetragonal

Crystal class:  4/m 2/m 2/m

Twinning:

Unit cell:

Colour:  Colourless, white

Diaphaneity:  Transparent to translucent

Luster:  Vitreous, pearly on basal cleavage

Habit:  Crystals dipyramidal, minute, rare; embedded masses

Hardness:  3.5 to 4

Specific gravity:  2.998

Cleavage:  2; {001} perfect, {011} distinct

Tenacity:

Streak:

Synonyms/varieties:

Comments: