The Rosyd showing is located in an adit on the east bank of the Thompson River, approximately 1.6 kilometres north of Lytton.
The area is underlain by Triassic Mount Lytton Complex dioritic intrusives and Middle and Upper Cretaceous Kingsvale Group volcanics and volcaniclastics. The Kingsvale Group is redefined to the Spius Creek Formation of the Spences Bridge Group (Geological Survey of Canada Map 42-1989). Limestone lenses occur within the volcanics. Major faults lie along the Fraser River.
A sheared limestone band lies within grey, biotite granite. Radioactive stringers with ankerite and hematite occur within the limestone. Shearing strikes 310 degrees and dips 75 degrees southwest. A sample assayed 0.052 per cent uranium (Minister of Mines Annual Report 1955). A 12 metre adit was driven in the limestone in 1955 but no uranium minerals were found.