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, and 23 kilometres east of Gold Bridge, B.C.

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.

The Brett Creek jade deposit is documented as the combined Greenbay and the 4-Ton occurrences. The 4-Ton showing is approximately 500 metres east of the Greenbay quarry.

In 2012, Gray Rock Resources Ltd. conducted a geological and geochemical assessment of their Silver Stream property, including nephrite and listwanite occurrences (Assessment Report 33490). The Greenbay jade quarry area was mapped and sampled by Gray Rock in 2016 and trenched in 2017 (Assessment Report 37320).