Chalcopyrite Pyrrhotite Sphalerite

Virtual Museum ID: 19-AME158

Specimen Summary

This sample contains some common sulphide minerals, some of which are the valuable ore minerals chalcopyrite (copper) and sphalerite (zinc). The other mineral, pyrrhotite, can sometimes host significant precious metals, but by itself is not valuable.

Since chalcopyrite and sphalerite are common amongst this collection, this description will focus on pyrrhotite. Pyrrhotite is an iron sulphide mineral that is bronze to dark black in colour. Due to much more cost-efficient sources of iron such as iron stone, it is not mined unless it includes some of a more valuable commodity such as gold or silver. One very interesting property of pyrrhotite is that it is variably magnetic. This property is based on having iron in the overall mixture of elements in the mineral. Varieties of pyrrhotite with less iron are more magnetic. Pyrrhotite is often found as a constituent in mafic rocks of igneous composition, and in that case, it is associated with a more valuable mineral called pentlandite.

This sample comes from the North Rock Mine near Fort Frances, Ontario. The mine was discovered by prospectors in 1958 and mined via shaft in 1972. On this property lots of mafic and ultramafic rocks can be found, some of which are basaltic pillow lavas.

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)

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Location Information

Sample Origin:

Fort Frances, Rainy River District, Ontario

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North Rock Mine

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15 (NAD 83)

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Specimen Details

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Chalcopyrite Pyrrhotite Sphalerite

Primary Mineral Formula:

CuFeS2, (Zn,Fe)S, Fe(1-x)S

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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.

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