The Promise Well occurrence is a small showing of tungsten mineralization, located on the shoreline on the north side of the entrance to Fish Egg Inlet, on the coast of the Coast Mountains, 27 kilometres south of the community of Namu.

The occurrence is in a small unit of granite to granodiorite, within a larger body of quartz diorite of the Jurassic to Tertiary Coast Plutonic Complex (Minister of Mines Annual Report 1953; Geological Survey of Canada Map 1386A). At the showing is a breccia of moderately to highly altered sedimentary fragments in a matrix of granite to granodiorite. The breccia is apparently not extensive, passing into massive granodiorite to the north.

The breccia contains quartz veins up to 15 centimetres thick in which there are a few grains of scheelite (Minister of Mines Annual Report 1953). The main quartz veins strike 035 degrees and dip 50 degrees northwest. A limited amount of stripping and shallow blasting has been done on the showing.