The old Minto mine is located on the north shore of Carpenter Lake, 8 kilometres north-east of Goldbridge, British Columbia.
The following quote is from B.C. Government site “Minfile”- Minfile No. 092JNE 066, current to 1991:
“The property is underlain by northwest trending argillites, cherty quartzites, ribbon cherts and volcanics of the Mississippian to Jurassic Bridge River complex. Upper Cretaceous dykes of feldspar porphyry, andesite porphyry, felsite and microdiorite cut north to northwest across the sediments, dipping steeply. Mineralization occurs in shear zones following the intrusive contact of porphyry dykes or the stratigraphic contact between sediments and volcanics. The strata, dykes and veins are offset by late strike-slip faults. The principal ore shoot occurs in cherty quartzites in a strong shear which follows, in part, along the footwall of a 6-metre wide, altered, fine-grained feldspar porphyry dyke (the "Minto dyke"). Veins up to 1.2 metres wide contain lenses and narrow bands of quartz, calcite and ankerite with coarsely crystalline arsenopyrite, pyrite, sphalerite, stibnite, pyrrhotite, galena, chalcopyrite and rare tetrahedrite, jamesonite, bismuth and gold.
Vein material generally has a banded structure defined by alternating metallic mineral concentrations and quartz-carbonate gangue. The vein also contains fragments of altered wallrock. Wallrock alteration is characterized by rare to abundant ankerite and calcite with lesser chlorite, sericite and mariposite.”
Comment by Giles Peatfield regarding the locality:
The Minto mine is one of several deposits near Carpenter Lake – see for instance Congress (B.C. Minfile No. 092JNE 029) and Lou (B.C. Minfile No. 092JNE 131), among others.
Comment by Giles Peatfield regarding the references:
I have included the references for papers by Gwyn (1938) and Margetts (1938), because they are listed in Minfile (Property File section) as referring to this property. However, it is important to note that these reports describe mineralogy that seems out of character for the mine, based on other works. After discussion with Dr. J. Douglas Scott, who has reviewed the Gwyn report in detail, we suspect it is possible that the specimens did not in fact come from the Minto mine. Should further information come to light, this decision could be revisited (25 March 2022).
Comments by Giles Peatfield regarding some of the minerals listed:
Ankerite: This was reported by Minfile, with no further information.
Bismuth: Cairnes (1943) reported small amounts of native bismuth; none of the other workers identified it in their examination of specimens of ore.
Jamesonite: Cairnes (1943) mentioned small amounts of jamesonite, but gave no further data. None of the other workers identified the mineral here. This has become somewhat problematic for the area, and should be regarded as tentative.
Mariposite: O’Grady (1937) described the mineral as “green chlorite”; others described it as mariposite, but see the note below for muscovite.
Muscovite (variety hydrated chromiferous muscovite): This mineral was reported by Pearson (1977) as hydrofuchsite, based on an analysis at the laboratory of the British Columbia Ministry of Energy, Mines and Petroleum Resources. He stated that “From this sample was separated 0.6 gram of green mineral thought to be the chromian phengite, mariposite. Analysis revealed that the mineral was hydrofuchsite . . . .” Dr. Scott suggests that hydrofuchsite should be regarded as a varietal name for a hydrated chromiferous muscovite.
Tetrahedrite: This has been described as being tentative or in very small amounts, with no hard analytical data. It can probably be regarded as valid for the locality.

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Standard Detailed Gallery Strunz Chemical Elements

Mineral List

14 valid minerals.