CHEMISTRY - Na8Al6Si6O24Cl2
CRYSTALLOGRAPHY - Cubic
CRYSTAL GROWTH AND HABITS - Sodalite rarely forms crystals (dodecahedrons). It is most commonly massive.
COLOR AND OTHER OPTICAL PROPERTIES - Color varies from colorless to white, yellow, green to blue and dark blue, even reddish.
HARDNESS - 5.5 - 6
SPECIFIC GRAVITY - 2.2 - 2.3
LUSTER - Vitreous to greasy
STREAK - White
BREAKABILITY - Poor cleavage; uneven to subconchoidal fracture; brittle
OCCURRENCE - Typically formed in nepheline syenites and related rocks.
ASSOCIATED MINERALS - Nepheline, garnets, aegerine, microcline, sanidine, albite, calcite, fluorite.
MINERAL NAME - Due to its high sodium content.