Sonedma is the second of the Amazon system's arid "super-terrestrial" worlds. It is considerably less dense than its neighbor Derneuca and has an atmosphere of carbon dioxide and ethane. Its frozen surface is mainly composed of iron-laced silicates with deposits of sulfur.
- Survey: UNC: Valuable Minerals: Rare Element ×1 (Polonium)
- Given the sulphur, the mineral most likely responsible for yielding the polonium is bismuth sulfide (Bi2S3), alias bismuthinite.