The I.X.L. (L.679) occurrence is located at an elevation of approximately 1020 metres on the east side of O.K. Mountain and 1.6 kilometres west of Rossland.
Regionally, the area is underlain by mudstone, siltstone, shale and fine clastic sedimentary rocks of the Carboniferous to Permian Mount Roberts Formation; basaltic volcanic rocks of the Lower Jurassic Elise Formation (Rossland Group) and trachytic volcanic rocks of the Eocene Marron Formation (Penticton Group). The sediments and volcanics have been intruded by syenitic to monzonitic rocks of the Eocene Coryell Plutonic Suite to the west and quartz monzonitic rocks of the Early Jurassic Rossland Plutonic Suite and granitic rocks of the Middle Jurassic Trail Pluton to the east.
The I.X.L. veins lie within greenstone and altered greenstone of the Lower Jurassic Elise Formation. These lie adjacent to the northern contact of a body of serpentinite, probably Permian, that trends east and probably dips steeply to the south. Many small shear zones along this contact suggest that it is an east-trending fault that is terminated by the Eocene Marron Group on the west and the Jumbo fault on the east. Irregular masses of monzonite of the Eocene Coryell Intrusions were encountered in the I.X.L. workings. Also, mafic and lamprophyre dikes, most of which trend northward, are widely distributed. The lamprophyre dikes occupy faults that cut and, in some places, have slightly displaced the quartz veins.
The Rossland greenstone is very fine grained, dense, and massive rock of dark-green to brownish hue. The original texture has been destroyed by both the development of chlorite and fibrous amphibole and by local silicification and serpentinization. It varies from a highly altered rock with small amounts of serpentine and magnetite to a mottled phase and then a phase that carries abundant, uniform serpentinite and magnetite. The typical massive serpentinite (Permian body) is a very dense black rock with cross-fibre asbestos infilling joints as 0.2- to 0.6-centimetre veinlets, and light-green talc has developed in the immediate vicinity of the faults. Ten samples of serpentinite taken from this area gave nickel assays of less than 0.24 per cent (Bulletin 74).
On the I.X.L. (L.679) the three principal veins strike 060 to 080 degrees and dip 35 to 75 degrees to the south. Widths range from a few centimetres to 0.5 metre and as much as 2 metres in a few places. The strongest mineralized zones are less than 100 metres long and have been developed approximately the same distance up dip. The quartz veins contain free gold, often visible to the naked eye. Mineable pockets of gold are erratically distributed in the veins. Although occasional concentrations do occur, sulphides are not common in the quartz veins. These sulphides include pyrite, chalcopyrite, galena, and sphalerite. Pyrite is also widely disseminated in the wallrock. The only other gangue mineral in addition to the quartz is ankeritic carbonate, which occurs in irregular areas in the vein and occasionally as veinlets in the surrounding rocks.
In 2015, a combined indicated mineral resource for the I.X.L. (MINFILE 082FSW116), O.K. (MINFILE 082FSW117) and Midnight (MINFILE 082FSW119) occurrences was reported at 48 000 tonnes grading 6.0 grams per tonne gold and 3.0 grams per tonne silver with an additional inferred mineral resource of 8000 tonnes grading 7.7 grams per tonne gold and 2.0 grams per tonne silver (Assessment Report 35609).
The I.X.L. (L.679) claim was staked by T. Heady in May 1891. The claim is adjoined by the Midnight (MINFILE 028FSW119) claim on the east and the O.K. (MINFILE 028FSW117) claim on the west. In 1899, the I.X.L. Gold Mining Company worked the property. Numerous lessees worked the property during the period of 1900 through 1948. Ownership of the claim had been acquired by J.S. Baker of Tacoma in approximately 1920. Kootenay Central Mines Ltd. leased the property in 1948 and reopened the No. 5 level, which is connected with the workings on the Midnight claim, also owned by the company at the time. Very little work was done by the company and lessees resumed operations in 1953.
Midnight Consolidated Mines Ltd. was formed in 1956 to develop the I.X.L., Midnight and O.K. mines; however, operations were suspended in April 1957. Subsequent mining operations were carried on by lessees.
The I.X.L. veins were mined intermittently for 53 years during 1899 through 1974, producing a total of 5248 tonnes of ore. Commodity recovery is recorded at 811 746 grams gold, 270 531 grams silver, 8255 kilograms copper, 256 kilograms lead and 154 kilograms zinc. Ore from the I.X.L. and Golden Drip (MINFILE 082FSW118) claims was stockpiled and milled between 1977 and 1984. Former workings include at least five adits, referred to as the I.X.L.-1A, -1, -2, -3 and -350 adits, and associated stopes.
In 1988, a portable mill and concentrator was planned to process an estimated 54 430 tonnes of dump material grading 24.0 grams per tonne gold (George Cross News Letter, September 23, 1988).
In 1993 and 1994, Matovich Mining Industries Ltd. completed a program of geological mapping, a 15.0 line-kilometre ground magnetic survey and 16 diamond drill holes, totalling 2210.0 metres, on the area. In 1996, Minefinders Corp. Ltd., on the behalf of Matovich Mining Industries Ltd., completed a program of underground rehabilitation, mapping and sampling and seven diamond drill holes, totalling 877.8 metres, on the area.
During 2002 through 2004, Matovich Mining Industries Ltd. completed programs of underground development on the Midnight and I.X.L. claims. In 2005, West High Yield Resources Ltd. completed a program of geological mapping and a 11.2 line-kilometre ground magnetic survey on the area. In 2014 and 2015, ground self-potential and VLF-EM surveys were completed.
