Copper Gold Silver Cobalt Zinc
Virtual Museum ID: 19-BCGS-HCA2
Native Copper is a form of copper that occurs as a natural mineral. It is uncombined. Copper rarely occurs in a native form as it usually occurs mixed with other elements or in oxidized states. Most of the copper that is produced is extracted from sulfide deposits. It is metallic, has an opaque diaphaneity, is soft and has an isometric crystal system. Copper is used as a conductor of electricity, specifically as wiring. It is also a conductor of heat and used to make cooking utensils. Copper is used to make alloys as well.
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. In its natural mineral form, gold is commonly alloyed with silver. Gold is distinguishable by its characteristic golden yellow colour and extreme heaviness.
Silver is an important precious metal. It is still highly valued today and has many important uses, as well as being used for jewellery. Silver has the highest electrical and thermal conductivity and reflectivity of all metals and is widely used in electronics and industrial chemistry. It is also used to make mirrors, photographic and x-ray film and collectible coins. Silver has natural antiseptic properties, therefore, has many different medical applications. Silver can occur in its elemental form as metallic silver, or in compounds and minerals with other elements like gold and lead. Silver has a distinct silver-grey colour and is soft and malleable, meaning it can be easily worked and shaped.
Cobalt is a ferromagnetic element. It is known to be hard, silver to white, and brittle. Cobalt is stable in air and unaffected by water. Most of the cobalt in the world is in Earth’s core. Cobalt is usually found in the form of ores. Cobalt is used in many alloys, magnets, as catalysts for the petroleum and chemical industries and as drying agents for paints.
Sphalerite is the main ore mineral for zinc, and although relatively common, finding it in commercial amounts is somewhat rarer. The zinc will give the mineral a yellow or red hue, but iron can replace the zinc in the atomic structure, making the crystals black. Rarely, cobalt finds its way into the structure, and produces green crystals. Although sphalerite is a relatively soft mineral, it can be cut (faceted) into attractive gems, which are used for mineral displays.
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:British Columbia Geological Survey (BCGS)
Virtual Museum ID:19-BCGS-HCA2
Date Added to VM:2019-05-07
Sample Origin:Near Observatory Inlet, B.C.
Specific Site:Hidden Creek (Anyox) mine
Datum:09 (NAD 83)
VM Category:Ore Sample
Primary Features:Copper Gold Silver Cobalt Zinc
Primary Mineral Formula:Cu Au Ag Co Zn
Primary Category:native element sulphide
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:Hazelton Group
Geological Period:Lower to lower Middle Jurassic
Stratigraphic Age:201.3 - 163.5 Ma
Geological Belt:Coast Crystalline
Geological Terrane:Stikine, Wrangell
Minfile ID:103P 021
The Hidden Creek (Anyox) mine, near Observatory Inlet and just west of Granby Bay, was a major copper producer between 1914 and 1936.
The area is underlain by the western margin of a 14.4 by 9.6 kilometre roof pendant within the Eocene Coast Plutonic Complex. Recent geochronology and fossil research by the Geological Survey of Canada have helped define the age of the pendant. These pendant rocks have been correlated with Lower to lower Middle Jurassic Hazelton Group rocks and overlying upper Middle to Upper Jurassic Bowser Lake Group sedimentary rocks (Geological Survey of Canada Open File 3453). The Hazelton rocks consist of variably chloritized pillowed and massive basalt with minor mafic tuffs. The overlying Bowser Lake sediments consist of siltstone and sandstone with minor chert and limestone. There are two observable phases of folding in the area, an initial north-northeast trending phase followed by a later east-northeast trending phase.
The Anyox deposit consists of eight distinct massive sulphide bodies, numbered 1 to 8, and a quartz vein stockwork containing disseminated sulphides. The underlying volcanics consist of tholeiitic pillow basalts and basaltic tuffs, with the frequency of tuff lenses and layers increasing upwards through the sequence. Chloritization, quartz veining and sulphide impregnation also increases upwards. A chert horizon, followed by a turbidite sequence of quartzofeldspathic silt and pelite metamorphosed to argillite, overlies the volcanics and massive sulphides.
The structure is dominated by an asymmetrical overturned anticline/syncline pair. The Number 1, 4, 5, 6, 7 and 8 orebodies occur along the volcanic/sediment contact, around the nose of the anticline which plunges north at 30 degrees. The Number 2 and 3 orebodies occur in volcanics, 30 to 100 metres west of the volcanic/sediment contact, on the west limb of a north plunging asymmetrical fold. A north striking, steeply east-dipping fault separates the Number 2 and 3 orebodies, which formed a single body before being displaced 90 metres vertically and 60 metres horizontally. The Number 2 and 3 orebodies strike north and dip steeply to the east, and the Number 1 body strikes north to northeast and dips 50 to 90 degrees to the west. The dimensions of the massive sulphide bodies range from 500 by 400 by 76 metres for the Number 1 deposit to 150 by 100 by 21 metres for the Number 6 deposit.
Two types of massive sulphide bodies are distinguished at Anyox. The more common type, which includes the Number 1, 4, 5, 6, 7 and 8 orebodies, consists of stratiform tabular to elongate massive sulphide orebodies interbedded with cherty metasediments on the volcanic/sediment contact. Mineralization consists primarily of pyrite and lesser pyrrhotite with chalcopyrite and sphalerite occurring as fine disseminations or as massive layers and lenses within the pyrite and pyrrhotite. The sulphides form massive layers up to 75 metres thick. Gangue minerals consist of quartz, chlorite, actinolite, tremolite, calcite, biotite and sericite.
The Number 2 and 3 orebodies characterize the second type which consists of massive stratabound layers and lenses of sulphides in basaltic tuff. The tuff has been altered to chlorite or chlorite actinolite schist. Mineralization consists of massive pyrrhotite, variable amounts of chalcopyrite and minor pyrite. The mineralization forms layers, lenses and disseminations in the tuff. Gangue minerals consist of quartz, chlorite, actinolite, hornblende, epidote and albite.
West of the Number 2 and 3 deposits, a stockwork of epigenetic quartz veins forms a low grade, unmined and poorly defined copper orebody. Mineralization consists of pyrrhotite, chalcopyrite, minor pyrite and trace sphalerite occurring as disseminations and blebs in chloritized metabasalt and quartz veins.
Between 1914 and 1936, 21,725,524 tonnes of copper ore were produced from the Number 1 to 6 bodies. The average grade was 1.4 per cent copper, 0.17 gram per tonne gold and 9.5 grams per tonne silver.
The North Hidden Creek showing, located 300 metres north of the mine, consists of two massive sulphide intersections obtained from 1982 drilling. The intersections occur above the basalt/argillite contact in hangingwall sedimentary rock units. A 6.1-metre intersection in Hole 82-9 assayed 2.5 per cent copper, 0.5 per cent zinc, 1.7 grams per tonne gold and 99.4 grams per tonne silver (Report by Taiga Consultants Ltd., 1992).
In 1983, Wright Engineers Limited estimated remaining ore reserves at Hidden Creek to be 77 million tonnes grading 0.55 per cent copper equivalent. In the same year, Cominco computerized the data and calculated a potential mineralized ore reserve, to a depth of 60 metres, of 45,360,000 tonnes grading 0.60 per cent copper, with a cutoff of 0.2 per cent copper (Report by Taiga Consultants Ltd., 1992).
In 1988, Glanville Management Ltd. concluded that open pit reserves present were 10.9 to 13.6 million tonnes, grading 0.70 to 0.75 per cent copper, with gold and zinc grades (Report by Taiga Consultants Ltd., 1992). This report and Assessment Report 23528 have a good summary and history of exploration in the Anyox area.
In 1992, Beacon Hill Consultants Ltd. outlined an indicated open pit reserve of 24,221,840 tonnes grading 1.08 per cent copper, 0.17 gram per tonne gold and 10.3 grams per tonne silver (George Cross News Letter No. 21 (February 1), 1993 and Report by Taiga Consultants Ltd., 1992).