Uranospinite

Formula: Ca(UO₂)₂(AsO₄)₂.10H₂O

Origin of name: from uranium and from Greek for sisking (finch), in allusion to its composition and color

Crystal system: Tetragonal

Crystal class: 4/m 2/m 2/m (synthetic, probable)

Twinning:

Unit cell: a = 7.17 Å, c = 20.61 Å

Colour: Lemon-yellow, yellow green to siskin green

Diaphaneity: Semitransparent

Luster: Waxy, pearly on {001}

Habit: Crystals thin rectangular plates (rare), small, aggregates

Hardness: 2 to 3

Specific gravity: 3.45

Cleavage: 2; {001} perfect, {100} distinct

Tenacity: Brittle

Streak: Light yellow

Synonyms/varieties:

Comments: fluoresces bright lemon-yellow under LW-UV, radioactive