Soddyite

Soddyite is a mineral of uranium. It has yellow crystals and usually mixed with curite in oxidized uranium ores. It is named after the British radiochemist and physicist Frederick Soddy (1877–1956). Soddyite has been a valid species since 1922, following its discovery in the locality of the Shinkolobwe uranium mine in the Haut-Katanga Province of the Democratic Republic of the Congo (DRC).^[2][3][4]

Soddyite
A piece of rock from Swambo in the Democratic Republic of Congo containing yellow crystals of soddyite
General
Category	Nesosilicates
Formula	(UO2)2SiO4·2H2O
IMA symbol	Sod[1]
Strunz classification	9.AK.05
Dana classification	53.03.03.01
Crystal system	Orthorhombic
Crystal class	Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m)
Space group	F ddd
Unit cell	1,745.03 ų
Identification
Color	Canary yellow to amber yellow
Cleavage	Perfect on {001}, good on {111}
Mohs scale hardness	3 - 4
Luster	Vitreous, greasy, dull
Streak	Yellow
Diaphaneity	Transparent, translucent, opaque
Density	4.627
Optical properties	Biaxial (-)
Refractive index	nα = 1.650 - 1.654, nβ = 1.685, nγ = 1.699 - 1.715
Birefringence	0.049 - 0.061
Dispersion	Relatively weak
Ultraviolet fluorescence	Weak orange yellow
Other characteristics	Radioactive