The Toughnut showing is located on Toad Mountain, 7 kilometres southeast of Nelson and 2 kilometres southeast of the Star showings (082FSW083). Old open pits, shafts and trenches occur on the property. This is probably a "conformable gold" occurrence.

The area, in the Silver King shear zone, is underlain by volcanic rocks of the Lower Jurassic Elise Formation, Rossland Group. These comprise mafic to intermediate flows, tuffs, breccia and quartz feldspar porphyry intruded by lamprophyre dykes. Porphyritic to equigranular zoned diorite-monzodiorite stocks of the co-magnetic Eagle Creek Plutonic Complex and Silver King Intrusive Complex intrude the Elise Formation. These units are then cut by younger lamprophyre dikes and Eocene aged Coryell alkalic intrusions. The units are deformed by the Silver King Shear Zone, a northwest striking shear zone. The contact between the Elise Formation and the Eagle Creek Plutonic Complex marks an up to 200-metre wide breccia and fault zone containing fragmentation and alteration of local units. The contact contains k-feldspar, sericite, quartz, chlorite, pyrite, chalcopyrite, and magnetite mineralization.

The showing consists of widely disseminated pyrite in volcanic rocks, and quartz veins hosting galena, chalcopyrite, sphalerite and rare tetrahedrite. Mineralization is associated with carbonate, sericite and potassically altered volcanic rocks. The alteration appears to be most prevalent in the tuffs.

The veins are 0.10 to 1 metre wide and many are parallel to the regional foliation, striking 120 degrees and dipping 75 degrees south. One vein, on which the workings were developed, can be traced discontinuously for at least 120 metres.

The highest assay from the 1989 trenching program was 6.2 grams per tonne gold, 1.7 grams per tonne silver, 0.0026 per cent copper, 0.0015 per cent lead and 0.0045 per cent zinc across 2 metres (Assessment Report 19503). Diamond-drilling in 1990 reported variable results (Assessment Report 20063).

The Toughnut occurrence is identified in a summary of historically significant drill intercepts on the Star-Toughnut Property. Highlighted zones include a grade of 4.99 grams per tonne gold, and 0.90 grams per tonne silver over 1.52 metres in hole 90-18, and 3.55 grams per tonne gold, and 7.94 grams per tonne silver over 3.30 metres in hole 90-16 (Payne, C. (2011-03-11): NI43-101 Technical Report – Compilation Report on the Star-Toughnut Property).