Andersonite

Formula:  Na₂Ca(UO₂)(CO₃)₃^.6H₂O

Origin of name:  For Charles Anderson, American geologist

Crystal system:  Hexagonal

Crystal class:  -3 2/m

Twinning:

Unit cell: a = 18.009 Å, c = 23.838 Å

Colour:  Yellow-green

Diaphaneity: Transparent to translucent

Luster:  Vitreous to pearly

Habit:  Crystals rhombohedral; clusters of minute pseudo-cubic crystals; thick crusts and veinlets

Hardness:  2.5

Specific gravity:  2.8

Cleavage:  None

Tenacity:

Streak:

Synonyms/varieties:

Comments:  Fluoresces bright yellow-green in both short and long UV. Found in sandstone-hosted uranium deposits.