Calcite Chalcopyrite Sphalerite

Specimen Summary

Calcite, a form of calcium carbonate, is a very common mineral found in many different geological settings. It is usually white, clear or very pale pink or yellow. It can look very similar to quartz but is easy to distinguish because it fizzes when it reacts with dilute hydrochloric acid. Calcite often occurs in veins or as fracture coatings or filling void spaces. Where crystals have enough time and space to fully form, calcite has a distinct rhombic shape. Calcite is the main mineral in limestone, marble and chalk, and is widely used in construction, agriculture and pharmaceutical industries.

Chalcopyrite is the most common ore mineral for copper and is a sulphide of iron and copper. Chalco comes from the Greek word chalko, meaning copper. Chalcopyrite is commonly found in sulphide deposits in most ore-forming environments. A characteristic deep brass yellow colour and iridescent green-to-purple weathering surfaces distinguish chalcopyrite from gold and sulphides such as pyrite.

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.

This sample comes from the Kinman Creek property south of Nimpkish Lake, about 50 km southeast of Port Hardy on Vancouver Island.

The sample is mostly brassy yellow chalcopyrite with small amounts of more silvery-yellow pyrite, sphalerite and calcite. It comes from a small copper porphyry type deposit, where an intrusive rock caused hot hydrothermal chemical solutions to circulate through the host volcanic rocks, forming veins with ore minerals as the solutions cooled. To date, no significant deposits have been found or mined in the Kinman Creek area.

Specimen Data

 

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.

Collection Details

Original Collection:

Association for Mineral Exploration (AME)

Sub Collection:

-

Collection ID:

AME-482

Virtual Museum ID:

19-AME482

Accessibility:

Date Added to VM:

2018-02-08

Location Information

Sample Origin:

Nimpkish Lake, BC

Specific Site:

Kinman Group

UTM Easting:

653093

UTM Northing:

5577752

Datum:

09 (NAD 83)

Coordinate Accuracy:

Approximate

Specimen Details

VM Category:

Mineral

Primary Features:

Calcite Chalcopyrite Sphalerite

Primary Mineral Formula:

CuFeS2, CaCO₃, CuFeS2, (Zn,Fe)S

Primary Category:

carbonate sulphide

Secondary Features:

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:

Vancouver

Geological Period:

Upper Triassic

Stratigraphic Age:

145 to 163.5 Million Years Ago

Geological Belt:

Insular

Geological Terrane:

Wrangell, Plutonic Rocks

Minfile ID:

092L 036

Minfile Link:

https://minfile.gov.bc.ca/Summary.aspx?minfilno=092L%20%20036

Site Details:

The Nimpkish Copper occurrence is located on the south side of Kinsman Creek, approximately 6.5 kilometres south east of the creek mouth on Nimpkish Lake and at an elevation of 640 metres.

The occurrence lies 500 metres east of East Hazel (092L 206) and several small showings occur in between the two.

The area is underlain by north striking Upper Triassic Vancouver Group, Karmutsen Formation tholeiitic basalts and overlying carbonates of the Quatsino Formation. Late Jurassic granodiorite of the Nimpkish batholith (which is part of the Jurassic Island Plutonic Suite) intrudes the Vancouver Group rocks. Strong regional north to northwest trending faults, often defining intrusive and lithological contacts, traverse the area.

The Nimpkish Copper occurrence is one of several skarn-limestone replacement deposits over a distance of 1.0 kilometre along the Nimpkish batholith western contact. Several lamprophyre dikes are present.

Mineralization consists of a 6 metre wide by 7 metre long and 14 metre high lens of massive chalcopyrite exposed in Copper Creek (the southeast continuation of Kinman Creek). The chalcopyrite body attains thicknesses of about 3.6 metres. The sulphide mineralization is accompanied variably and locally by magnetite, marcasite, covellite, bornite, molybdenite, greenockite and skarn minerals such as garnet, epidote, actinolite, calcite, quartz, chlorite and sericite.

Samples assayed between 4.8 and 13.03 grams per tonne gold, 81.6 to 104.6 grams per tonne silver, 11.46 to 13.75 per cent copper and 0.30 to 0.60 per cent zinc (Geological Survey of Canada Memoir 272, page 72). In 1989, a sample of massive chalcopyrite and pyrrhotite from the Kinman adit assayed 79 grams per tonne silver, 5.6 grams per tonne gold, 12.6 per cent copper and 0.145 per cent zinc (Assessment Report 20092).

The mineralized lens is estimated to contain 2014 tonnes of ore grading 13.75 per cent copper, 0.60 per cent zinc and 104.3 grams per tonne silver (Assessment Report 25764).

Twenty metres to the west lies a lens of massive chalcopyrite and calcite. Copper values assayed 0.18 to 0.67 per cent with trace to 0.1 per cent zinc. Gold and silver are present only in trace amounts (Geological Survey of Canada Memoir 272).

In 1928, E.L. Kinman and Associates discovered the main showings. In 1929 and 1930, Cominco optioned the tenures and completed surface trenching, twenty diamond drill holes, totalling 2010 metres, and a 52.5 metre adit. In 1962, Camloc Copper completed a program of geological mapping and a 0.7 kilometre magnetometer survey on the area as the Hazel Group. In 1966, Empire Development completed a program of ground geophysical surveys and geological mapping on the area as the Alpha, Hazel and Pie claims, Kinman property. In 1989, W.J. Laird completed a program of rock sampling and geological mapping on the area to the west as the Nimpkish claims. In 1998 and 1999, Doublestar Resources completed programs of prospecting and ground geophysical surveys on the area as the 2Star claim group. In 2010 and 2012, Selkirk Metals completed programs of prospecting and rock sampling.

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