A 500-metre long, east-west trending pegmatite lens occurs in light-grey to white granite of the Jurassic/Cretaceous Nelson Plutonics. The core of the pegmatite is quartz, which analysed 98.84 per cent SiO2, 0.42 per cent Al2O3, 0.04 per cent total iron, and 0.06 per cent CaO (Annual Report 1964). At the northwest limit the quartz lenses out into coarse-grained perthite. Here crystals of euxenite associated with magnetite occur in orthoclase.

The area to the south and east of the showing is high in uranium silts (over 50 parts per million) and uranium waters (up to 43.0 parts per billion) (Paper 1979-6).