Soddyite is a mineral of uranium with chemical formula: (UO2)2SiO4·2H2O. It has yellow crystals and usually mixed with curite in oxidized uranium ores. It is named after Frederick Soddy (1877–1956), British radiochemist and physicist.[1][2][3]
| Soddyite |
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 A piece of rock from Swambo in the Democratic Republic of Congo containing yellow crystals of soddyite |
| General |
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| Category | Nesosilicates |
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Formula
(repeating unit) | (UO2)2SiO4·2H2O |
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| Strunz classification | 9.AK.05 |
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| Crystal system | Orthorhombic |
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| Crystal class | Dipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m) |
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| Space group | Fddd |
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| Identification |
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| Color | Canary yellow to amber yellow |
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| Mohs scale hardness | 3 - 4 |
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| Luster | Vitreous, greasy, dull |
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| Diaphaneity | Transparent, Translucent, Opaque |
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| Optical properties | Biaxial (-) |
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| Refractive index | nα = 1.650 - 1.654, nβ = 1.685, nγ = 1.699 - 1.715 |
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| Birefringence | δ = 0.049 - 0.061 |
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| Dispersion | Relatively weak |
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| Other characteristics |  Radioactive |
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