Gold in quartz
Virtual Museum ID: 19-RM30
Gold is a valuable, highly prized mineral used in everything from jewellery to electronics and dentistry. Gold is desirable due to its special properties, such as malleability and resistance to tarnishing. Gold is commonly microscopic or embedded within or around sulphide grains. Free visible gold occurs as disseminated grains, or rarely as crystals. Crystals of gold commonly form within or around quartz, as seen in this sample. In its natural mineral form, gold is commonly alloyed with silver. Gold is distinguishable by its characteristic golden yellow colour and extreme heaviness.
The information listed below relates to the current holding location or collection that the sample is from, and whether the item is viewable at that location or is part of a private collection. Coordinates are given as guides, and we remind you that collecting specimens from these locations is not allowed. Caution is advised visiting such sites and Below BC assumes no responsibility for any injuries or trespassing charges that may occur as a result of the viewer entering these sites.
Original Collection:Rossland Museum & Discovery Centre (RM)
Virtual Museum ID:19-RM30
Date Added to VM:2019-06-09
Sample Origin:Burton, B.C.
Specific Site:Tillicum Mt.
Datum:11 (NAD 83)
Primary Features:Gold in quartz
Primary Mineral Formula:SiO2 · Au
Primary Category:native element oxide
Advanced Geological Information
The following section provides geological data relating to the specimen or the site it was collected from, when available. Information has been obtained from various sources including private and government datasets but may not be up to date. Any geological time periods or ages listed often relate to the primary geology of the area, and may not be the actual date of an event such as mineral formation.
Geological Formation:Rossland Group
Geological Period:Lower Jurassic
Stratigraphic Age:178.9 to 185.6 Million Years
The Tillicum (Heino-Money) occurrence is located at approximately 2130 metres elevation on a north- trending spur of Tillicum Mountain and approximately 12 kilometres east of the Lower Arrow Lake community of Burton.
Regionally, metavolcanic rocks and a predominant metasedimentary succession form the highly deformed, east-trending Nemo Lakes Belt. It is intruded to the north and west by the Jurassic and/or Cretaceous Goatcanyon-Halifax Creeks quartz monzonite stock, while to the south it is invaded by the Eocene Nemo Lakes quartz monzonite stock. Supracrustal rocks of the Nemo Lakes Belt in the Tillicum Mountain area are dominated by metamorphosed siltstone, calcareous siltstone, arkose, and wacke, with lesser amounts of basalt, tuff, argillite, impure carbonate and marble layers. The supracrustal rocks underwent a post-Lower Jurassic phase of regional metamorphism and folding that predates the Middle to Upper Jurassic intrusion of the monzonitic stocks. This resulted in sillimanite- grade metamorphism throughout most of the Nemo Lakes Belt, however, the metamorphic grade is lower around Tillicum Mountain and resulted in the formation of biotite, muscovite, chlorite and amphibole. In addition to the regional metamorphism, the rocks were locally subjected to two episodes of contact metamorphism. The first is associated with swarms of dioritic sills that probably accompanied the regional deformation;, the second is hornfelsing related to the intrusion of the large monzonitic stocks and postdates the regional deformation.
On the Tillicum property, the metamorphosed sedimentary rocks appear to correlate with the Lower and Middle Jurassic Archibald and Hall formations and the metamorphosed volcanic rocks with the older Lower Jurassic Elise Formation. All formations belong to the Lower Jurassic Rossland Group. These country rocks are intruded by swarms of deformed, often schistose, feldspar porphyritic diorite to quartz diorite sills that vary from 1 to greater than 100 metres in width. These intrusive rocks are widely distributed and are spatially and probably genetically related to gold-rich skarn mineralization on the Tillicum property. The country rocks immediately adjacent to the sills are often weakly hornfelsed. Locally the margins of some diorite sills and country rock adjacent to them are overprinted with skarn alteration.
The structure on the property is complex and is dominated by steep angle normal and reverse faults. Most faults have little offsets, however, several faults with major displacements divide the property into fault-bounded blocks. The metamorphic fabric of the rock closely parallels the bedding planes with minor or parasitic folding only very rarely observed. The Heino-Money zone is offset by a series of left-lateral, steep- angle, northeast- striking faults that have displacements of up to 9.0 metres. Within a 500 metre radius of the Heino-Money zone, three other significant mineralized zones have been discovered. These are the East Ridge zone, the Jenny zone and the Blue zone.
At the Heino-Money (Screamer) zone, strata-bound, gold-bearing, siliceous calc-silicate skarn alteration is hosted in a thin, wedge-shaped package of basaltic tuff and tuffaceous sedimentary rocks, which is bounded to the west by metabasalts and to the east by a large, altered feldspar porphyritic diorite body. The skarn is pinkish-green and is generally well layered with sub-parallel thin quartz veins and variable amounts of sulphides. The skarn assemblage includes quartz, tremolite-actinolite, clinozoisite, plagioclase, diopside, biotite, garnet and microcline, with minor amounts of sericite and carbonate. Free gold occurs as fine to coarse disseminations and fracture fillings within and along walls of the quartz sulphide veins; gold is generally associated with pyrrhotite, pyrite, galena and sphalerite. The zone is cut by north-trending, steeply dipping lamprophyre dykes, which postdate both the skarn development and sulphide mineralization. A polished section study of this mineralization shows that gold grains are generally free, but may also be intimately associated with pyrrhotite, arsenopyrite, sphalerite and pyrite-marcasite. Some pyrrhotite grains are rimmed with colloform pyrite-marcasite while others contain small masses of hematite and graphitic material. Minor to trace amounts of tetrahedrite, chalcopyrite and possibly electrum also occur. Polished thin section studies and geochemical studies suggest that the mineralizing process at the Heino-Money zone involved two phases of precious metal deposition. The first phase included the introduction of gold, arsenopyrite and possibly sphalerite, accompanied by the crystallization of quartz, carbonate and calc-silicate minerals. This was followed by the deposition of argentiferous galena and the continued introduction of arsenopyrite and sphalerite. Gold and silver-bearing horizons are present in the skarns at the Heino-Money zone but they do not occur together. Silver is probably carried in galena.
In 1983, drilling outlined a drill-indicated reserve of 36,287 tonnes at 20.5 grams per tonne gold and a total inferred potential of 90,720 tonnes (George Cross News Letter, February 28, 1984). In 1989, the Heino-Money zone was explored by drilling and underground exploration and had a reported reserve potential of 45,355 tonnes grading 34.28 grams per tonne gold. Within this reserve, a mining reserve has been calculated to be 15,874 tonnes with a diluted grade of 34.28 grams per tonne gold using a cut-off grade of 11.99 grams per tonne gold. The mining reserve is outlined in four south- raking shoots that occur in a near vertical gold-bearing skarn structure that averages approximately 2 metres in width along a strike length of approximately 200 metres and a vertical extent of 100 metres. Additional reserve potential occurs between the delineated shoots as well as along strike and depth projections of the skarn structure (Assessment Report 19437). Columbia Gold Mines (1991), formerly Esperanza, estimated reserves of the Heino-Money zone to be 13,600 tonnes grading 34.79 grams per tonne gold (Information Circular 1993-13, page 17).
In 1981, a bulk sample of 58 tonnes shipped from the Money Pit averaged 78.8 grams per tonne gold. In 1986, a 3175- tonne bulk sample was shipped to the Dankoe mill at Keremeos and yielded 109.44 kilograms of gold (Assessment Report 19437). In 1993, as a result of mining at the Heino-Money zone, a total of 5503 tonnes of ore with an estimated head grade of 24.4 grams per tonne gold was shipped to the Goldstream mill (MINFILE 082M 141) for processing. Approximately 102,443 grams of gold and 149,546 grams of silver were recovered into concentrates that were shipped to Japan for smelting (George Cross News Letter No. 237 (December 10), 1993).
The East Ridge zone is 300 metres east of the Heino-Money zone. Gold mineralization occurs in a blanket-like zone that straddles the contact between porphyritic diorite and meta-arkose, quartzite, siltstone and minor argillite. The gold-bearing, near-vertical calc-silicate skarn structures occur within a 9.1 to 24.3- metre zone that strikes northeast and dips 70 degrees northwest. The skarn structures have widths that vary from 1.5 to 4.6 metres, but average 2.1 metres. The East Ridge zone has been traced by drilling for 1100 metres along strike and 365 metres down-dip at an average width of 1.5 metres. The East Ridge zone is comprised of two parallel upper skarn structures 0.9 to 1.5 metres thick and a lower skarn structure. Gold occurs in randomly distributed high- grade pockets separated by areas of lower grade material. Within the zone, gold-bearing sulphide mineralization consists of pyrrhotite, pyrite-marcasite, arsenopyrite, chalcopyrite, sphalerite, galena and native gold with traces of tetrahedrite.
In 1982, a 180- kilogram bulk sample from the upper cut assayed 3.8 grams per tonne gold (Assessment Report 11161). In 1984, drilling on the East Zone yielded an inferred resource of 4,536,000 tonnes at 1.7 grams per tonne gold (Northern Miner, November 15, 1984). In 1989, exploratory underground drifting (300 metres) and drilling on the East Ridge zone resulted in indicated reserves of 1,184,672 tonnes grading 5.82 grams per tonne gold. Within this reserve are measured geological reserves of 238,567 tonnes grading 13.36 grams per tonne gold using a minimum width of 1.5 metres and a cut-off grade of 6.85 grams per tonne gold (Assessment Report 19437). Columbia Gold Mines (1991) estimated reserves of the East Ridge zone to be 440,000 tonnes grading 10.26 grams per tonne gold (Information Circular 1993-13). In 1997, a drill- indicated reserve of 474,640 tonnes averaging 9.6 grams per tonne gold with a total possible resource of 1,063,220 tonnes averaging 8.9 grams per tonne gold with a cut-off grade of 5.1 grams per tonne gold was reported (Assessment Report 25004).
The Jenny zone is 150 metres north and 100 metres lower in elevation than the Heino-Money zone. The Jenny zone consists of alternating bands of glassy quartz and sericitic quartzite overlain by pyritic, black, fine-grained, thinly bedded argillite. Very fine -grained galena, sphalerite and pyrite occur in the quartzite with euhedral magnetite and pyrite in the glassy quartz. Occasional cavity fillings of gold-bearing chalcedonic quartz and actinolite- rich bands are also evident. In 1982, diamond drilling, on the zone, yielded up to 4.5 grams per tonne gold over 3.0 metres from drill hole S82-5 (Assessment Report 11161). Also at this time, a chip sample across 0.4 metres returned 12.9 grams per tonne gold and 19.8 grams per tonne silver (Assessment Report 11161). In 1997, sampling of the Lower Jenny zone, located another 50 metres north, yielded up to 7.6 grams per tonne gold and grams per tonne silver, while a select sample assayed 413.9 grams per tonne gold (Assessment Report 25004).
The Blue (BBB) zone is 280 metres north-northeast of the Heino-Money zone. Three pits expose pyrite, pyrrhotite, galena and sphalerite massive stringers and lenses within a fractured and sheared, thinly bedded quartz-biotite gneiss. Just above the pits, scheelite occurs disseminated in a siliceous matrix and along fractures. In 1982, sampling yielded values up to 6.9 grams per tonne gold (Assessment Report 11161).
The Tillicum group, comprising the Tillicum, Cultus and Valley View claims, was apparently located in this vicinity. During 1917 through 1921, owners J. G. Reveler and L. Robson carried out exploration work in one or more short drift adits for approximately 75 metres. Approximately 3.3 tonnes of sorted ore averaging 66.2 grams per tonne gold and 3420 grams per tonne silver was stockpiled in 1921 (Assessment Report 07909). The Tillicum portal is located at approximately 150 metres to the south east of Heino-Money pit zone and at an elevation of 2160 metres.
In 1979 and 1980, the area was prospected by Arnold and Elaine Gustafson, of Burton, on ground held as the Wolf, Hugh, Sandy and Near claim groups (12 units). This led to the discovery of high-grade gold in the "Money Pit" area in September 1980. Esperanza Explorations Ltd and Welcome North Mines Ltd., as a joint venture, optioned 100 per cent interest in the property from the Gustafson's by a September 20, 1980, agreement, subject to a percentage of net smelter returns. The existing claims and adjacent ground was over staked as the Til 1-4 claims (72 units). Work in 1981 included geochemical and geophysical surveys, bulk sampling and trenching.
Welcome North withdrew from the joint venture in March 1982. On June 23, 1982, La Teko Resources Ltd. acquired an option to purchase a 50.4 per cent share interest in Esperanza Explorations prior to December 31, 1984 for $5,125,000. Additional staking expanded the property to some 237 units. Exploration activity in 1982 included 1128 metres of diamond drilling in 16 holes on the Heino-Money zone, eight holes on the East Ridge zone and three holes on the Jenny zone. In 1983, a 60.9-metre crosscut adit was driven on the East Ridge zone and further geochemical surveys and trenching carried out. Diamond drilling was done in 18 holes on the Heino-Money zone. Drilling in 1983 totalled 2319 metres in 38 holes. In 1984, a 60-metre adit was driven into the upper part of the Heino-Money zone. Further diamond drilling was done in five holes on the East Ridge zone. La Teko provided financing of exploration to the end of 1985 ($2.28 million) to earn a 39.6 per cent interest in Esperanza. La Teko was unable to provide further financing and the 1982 option agreement expired at the end of 1985. In 1986, Esperanza Explorations completed a drill program of 25 surface diamond drill holes, totalling 835.5 metres and nine underground diamond drill holes, totalling 176.8 metres. Underground development, during this time, included 153 metres of drifting and 46.5 metres of raises. By this time 5 levels had been developed at elevations of 2112, 2130, 2148, 2160 and 2171 metres on the Heino-Money zone. In 1989, a further 10 diamond drill holes, totalling 1437.6 metres, were completed on the East Ridge zone.
In 1997, AMT Resources and IBEX Resources completed a program of geochemical sampling, trenching and a ground electromagnetic survey on the area. In 2001 and 2002, 1330275 Ontario Limited completed programs of rock, silt and soil sampling and geological mapping on the area. During 2008 through 2014, AMT Industries Canada completed programs of soil sampling, a ground electromagnetic survey and remote sensing analysis on the area.