Uranopilite

Formula: (UO₂)₆(SO₄)(OH)₁₀.12H₂O

Origin of name: from composition and Greek for felt, alluding to the composition and habit

Crystal system: monoclinic

Crystal class: unknown

Twinning:

Unit cell:  a = 14.03, b = 14.60, c = 9.184, β = 96.87°

Colour: Bright lemon-yellow, golden yellow, yellow to straw-yellow

Diaphaneity: Semitransparent

Luster: Silky

Habit: Crystals lath-like, tiny, in rosettes and globular aggregates, felted crusts, films

Hardness: 1

Specific gravity: 3.7-4

Cleavage: 1; {010} perfect

Tenacity: 

Streak: 

Synonyms/varieties:

Comments: fluoresces bright greenish yellow under SW-UV and LW-UV, radioactive