Parsonsite is a lead uranium phosphate mineral with chemical formula: Pb₂(UO₂)(PO₄)₂·2H₂O. Parsonsite contains about 45% lead and 25% uranium. It forms elongated lathlike pseudo monoclinic crystals, radial spherulites, encrustations and powdery aggregates. It is of a light yellow colour. It has a Mohs hardness of 2.5-3 and a specific gravity of 5.72 - 6.29.^[3][4]

Parsonsite
Yellow brown parsonsite crystals with green torbernite from the Pinhal do Souto mine, Mangualde, Viseu District, Portugal
General
Category	Phosphate mineral
Formula (repeating unit)	Pb2(UO2)(PO4)2·2H2O
IMA symbol	Pso[1]
Strunz classification	8.EA.10
Crystal system	Triclinic
Crystal class	Pinacoidal (1) (same H-M symbol)
Space group	P1
Identification
Color	Pale citron-yellow
Crystal habit	Elongate and flattened tiny crystals, may resemble laths, crusts, powdery aggregates
Cleavage	None observed
Mohs scale hardness	2.5-3
Luster	Sub-adamantine
Diaphaneity	Transparent to translucent
Specific gravity	5.37
Optical properties	Pale yellow color
Pleochroism	None
Ultraviolet fluorescence	Does not fluoresce in UV light
Solubility	Soluble in acids
Other characteristics	Radioactive
References	[2]

It was first described in 1923 for an occurrence in the Shinkolobwe mine, Katanga Copper Crescent, Democratic Republic of Congo. It was named for mineralogist Arthur Leonard Parsons (1873–1957) of the University of Toronto, Canada.^[4][5]