The Rainbow occurrence is located south of a northwest-flowing tributary of the Quatse River referred to as Edith Creek, approximately 4.5 kilometres east of Quatse Lake.
Regionally, the area is underlain by northwest-trending belts of basaltic volcanics and carbonate sedimentary rocks of the Upper Triassic Karmutsen and Quatsino formations (Vancouver Group) and mafic volcanics and sediments of the Upper Triassic to Lower Jurassic Bonanza Group (Holberg volcanic unit, Nahwitti River wacke and Parson Bay Formation). These volcanic and sedimentary rocks have been intruded by granodioritic rocks of the Early to Middle Jurassic Island Plutonic Suite.
Locally, skarn zones are spread out along a strike length of 500 metres and have widths of up to 18 metres. Skarn is erratically developed in narrow beds of limestone and along limestone-volcanic (andesite, basalt) contacts. The hostrocks strike 070 degrees and dip 035 degrees south. Stratigraphically, the limestones and volcanics lie near the top of the Karmutsen Formation. The rocks have been intruded by andesite dikes and quartz diorite. The skarn consists of grossularite disseminated with chalcopyrite and minor magnetite (‘brown ore’) and hedenbergite, hornblende, tremolite, actinolite, ilvaite, magnetite and sphalerite and disseminated chalcopyrite (‘black ore’). Malachite, azurite, limonite and hematite can be found at surface.
In 1963, drillhole LJ-1 is reported to have yielded up to 2.23 per cent copper over 1.35 metres (Assessment Report 8284).
In 1980, two 18-kilogram samples assayed3.070 per cent copper, 0.11 per cent zinc, 66.85 grams per tonne silver, 0.02 per cent lead and 0.10 gram per tonne gold (‘brown ore’) and 4.88 per cent copper, 4.42 per cent zinc, 91.87 grams per tonne silver, 0.10 per cent lead and 0.14 gram per tonne gold (‘black ore’), respectively (Assessment Report 8284).
In 1989, trenching yielded up to 2.03 per cent copper with 24.4 grams per tonne silver over 1.0 metre (sample 6910) from trench 89-13 and 1.09 per cent copper with 20.3 grams per tonne silver over 2.0 metres (sample 6908) from trench 89-14 (Assessment Report 19423).
In 1963, Port Hardy Copper Mines Ltd. completed four drillholes, totalling 167.4 metres. In 1968, Dawn Minerals soil sampled the area. Also, at this time, Emperor Mines completed an airborne magnetic survey on the area immediately north. In 1969, Yellowknife Bear Mines Ltd. completed a program of soil sampling and a 49.6 line-kilometre ground magnetic survey on the area as the Little Joe claims. In 1980, a program of geological mapping and geochemical sampling was completed. In 1981 and 1983, Energex Minerals Ltd. completed an airborne electromagnetic survey and eight diamond drill holes, totalling 232.4 metres, on the area as the Cliff claims. During 1987 through 1989, programs of rock and soil sampling, geological mapping, minor trenching and 16.7 line-kilometres of ground magnetic surveys were completed on the area.
In 1991 and 1992, Daiwan Engineering Ltd. completed programs of prospecting, geochemical sampling and ground geophysical surveys the area immediately north as the Marisa 1-4 claims.
In 2016, the area was prospected by Tech-X Resources Ltd.
