Tychite

Formula: Na₆Mg₂(CO₃)₄(SO₄)

Origin of name: from Greek for luck

Crystal system: cubic

Crystal class: 2/m -3

Twinning:

Unit cell: a = 13.89 Å

Colour: colourless

Diaphaneity: transparent

Luster: vitreous

Habit: crystals octahedral, may have cube faces

Hardness: 3.5 to 4

Specific gravity: 2.55

Cleavage: none

Tenacity: 

Streak: 

Synonyms/varieties:

Comments: series with ferrotychite