The 4-Ton nephrite showing is 0.5 kilometre east of Brett Creek, 1.25 kilometres north of the confluence of Brett Creek with Marshall Creek.

At the showing, lenses and pods of nephrite occur within serpentinite (probably derived from the Permian and older Shulaps Ultramafic Complex) and its sheared contact with adjacent rocks of the Bridge River Complex (Group) (generally phyllite and rocks regionally metamorphosed to greenschist grade). Approximately 1.5 tonnes of extremely foliated and altered nephrite were excavated but were not of marketable quality.