The Little Gem prospect, a hypothermal cobalt-sulpharsenide uranium and gold vein, 2.3 kilometres east northeast of Dickson Peak, lies within the margin of the Jurassic to Eocene Coast Plutonic Complex (Cretaceous Penrose lobe pluton). Host rocks consist of granodiorite, minor hornblende-biotite-quartz diorite, diorite and gabbro, which are intruded by feldspar porphyry dykes. A broad, east trending and steeply south dipping fault zone cuts the granodiorite near the eastern contact with older sedimentary and volcanic rocks of the Mississippian to Jurassic Bridge River Complex (Group).

Shears in the zone contain two parallel ore shoots ranging in width from a few centimetres to a few metres. Irregular lenses of almost solid sulphides contain cobalt and gold values in association with danaite, loellingite, safflorite, arsenopyrite, scheelite and minor molybdenum. Uranium, in the form of uraninite, occurs in the gangue along with coarse-grained allanite, apatite, feldspar, quartz, chlorite, sericite, calcite, erythrite and limonite. Gold occurs mainly as microscopic veinlets of the native metal within and adjacent to the sulpharsenide minerals. Surrounding the ore, strongly bleached and sericitized granodiorite containing disseminated sulphides, residual quartz, feldspar and kaolin grades into unaltered granodiorite. The metallic minerals occur with the gangue in coarsely crystalline masses but are in general younger than most of the gangue minerals. The combination of the batholithic host rocks and the association of uraninite with hornblende, biotite, apatite, allanite, monazite, orthoclase, cobalt sulpharsenides, arsenopyrite and molybdenite is indicative of high temperature, possibly magma-derived, hydrothermal fluids.

Two adits follow the ore shoots. The upper adit, sampled over 36 metres and 90 centimetres width, graded 26.2 grams per tonne gold, 0.39 per cent uranium and 3.1 per cent cobalt; the lower adit, sampled over 1.8 metres, graded 54.8 grams per tonne gold, 0.3 per cent uranium, and 3.2 per cent cobalt (Rutherford, 1952 - Property File). Allen (1955), in Property File, reports an indicated resource of 4740 tonnes, grading 23.04 grams per tonne gold, 2.974 per cent cobalt and 0.212 per cent uranium (0.2499 per cent U3O8). In 1979, reserves were calculated at 27,705 tonnes grading 21.74 grams per tonne gold, and 2.045 per cent cobalt (George Cross News Letter No. 87, 1979). Stevenson, in 1948, estimated probable ore of 894 tonnes grading 0.18 per cent uranium (Property File). The Canadian Mines Handbook 1974-75 records 18,140 tonnes averaging 22.64 grams per tonne gold, 3.0 per cent cobalt and 0.2 per cent uranium (Canadian Mines Handbook 1974-75, page 251). Arsenic grades 25 to 27 per cent (Assessment Report 15451).

In 2007, a rock sample (JTSUG-4) of quartz-rich rock hosting pyrite from the No.3 level underground workings yielded 130.90 grams per tonne gold and 2.126 per cent cobalt (Shearer, J.T. [2008-05-02]: Technical Report on the Little Gem Cobalt-Gold Property, Gold Bridge/Bralorne Area, South-Central British Columbia, Lillooet Mining Division).

Work History

The deposits were discovered and staked by William Haylmore and W.H. Ball in 1934. Their interests were bought by J.M. and R.R. Taylor in 1937. The United States Vanadium Corporation optioned the property in 1937 and drove the upper tunnel. All work in Canada was terminated in 1939 by the above-named company and the exploratory program on the Northern Gem was not completed. During the winter of 1939 the lower tunnel was driven by contractors for J.M. and R.R. Taylor.

In 1940 the property was optioned for a short time by Bralorne Mines and the two short raises were driven from the lower tunnel. The lack of a treatment process, and indefinite marketing possibilities at that time, resulted in the option being dropped by Bralorne Mines.

In 1952 Estella Mines optioned the property. A switchback road was completed from Gun Creek bridge to the camp and twelve holes were diamond drilled from the lower tunnel. Estella Mines were forced to drop the option when they were unable to meet the due payment in November 1953 and it was not possible to secure an extension from the owners. Northern Gem Mining Corporation was formed in December 1955 for the purpose of acquiring and developing the property. Work was commenced on the road in June, on the camp in August and on the showings shortly thereafter. Work was terminated for the winter October 23rd because of the unusually early arrival of winter snow at the property.

Major Resources Ltd. held the property in 1979 and conducted airborne magnetometer, VLF-EM and radiometric surveys. Anvil Resources Ltd. held the property in 1986 and drilled 2 holes totalling 373.8 metres.

Ownership of the eight Little Gem claims reverted to the Crown in 2004. The property was acquired by B.N. Church and R.H. McMillan in 2007. Geological, geochemical, and rock sampling evaluations were completed between 2007 and 2009.

Cobalt One Energy Corporation Inc. acquired the property in 2018, and subsequently conducted stream sediment sampling and rock geochemistry.