Feldspar Mica Schist
Virtual Museum ID: 19-BCGS-HRC1
Feldspar is the most common mineral group found on the surface of the earth, comprising 41% of the Earth's continental crust by weight. Feldspar is a group of minerals that consist of aluminum and silicate minerals. Can be split into 2 major subgroups Alkali feldspar and Plagioclase.
Schist is a medium-grade strongly foliated metamorphic rock formed from mudstone or shale. Must have more than 50% platy and elongated minerals(micas/talc) to be considered a schist according to Cambridge Guide to Minerals, Rocks and Fossils.
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-HRC1
Date Added to VM:2019-05-07
Sample Origin:20 km SW of Kimberley, B.C.
Specific Site:Hellroaring Creek
Datum:11 (NAD 83)
Primary Features:Feldspar Mica Schist
Primary Mineral Formula:-
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:Creston Formation/Aldridge Formation: Helikian Purcell Supergroup
Geological Terrane:Ancestral North America
The Hellroaring Creek pegmatite stock is about 20 kilometres southwest of Kimberley and 31 kilometres west-northwest of Cranbrook. The stock has been explored for feldspar, quartz, mica and, in the 1960's, beryllium.
The area is underlain by quartzite and argillite of the Creston Formation and argillite, quartzite and mica schist of the Aldridge Formation, both of the Helikian Purcell Supergroup. These metasediments are intruded by sills and dykes of granodiorite of the Proterozoic Moyie Intrusions, which are in turn intruded by pegmatite of the Middle Proterozoic Hellroaring Creek stock. The east trending St. Mary fault separates this area from the area underlain by Creston Formation metasediments to the south. The Aldridge Formation is folded into an open northwest plunging anticline with the Hellroaring Creek stock emplaced in the core.
The pegmatite stock trends north-northwest for 4 kilometres within the Aldrige Formation and is up to 1.5 kilometres wide. The stock appears to be a series of large dyke swarms. Most of the sampling and diamond drilling is concentrated in an area at the north end of the stock, where drilling encountered thicknesses of up to 150 metres.
The stock is comprised of medium to coarse grained white to light grey pegmatite typically containing 60 to 70 per cent feldspar, 20 to 30 per cent quartz, 0 to 10 per cent muscovite and 0 to 10 per cent tourmaline. Beryl, garnet, pyrite, pyrrhotite, galena and arsenopyrite occur in minor to trace amounts. The feldspar occurs in distinct microcline and albite rich zones. Quartz occurs in massive lenses several metres thick that are free of feldspar. Muscovite forms fine flakes along fractures and books, up to 13 centimetres across, in irregular patches. Thin needle-like tourmaline crystals (3 by 10 millimetres) and blades up to 3 centimetres long occur in patches. Beryl forms erratically scattered very pale bluish green and white crystals and irregular masses up to 7.5 centimetres in diameter and 15 centimetres in length that tend to be associated with plagioclase, quartz and muscovite. Garnet is present as pink to red grains 1 to 2 millimetres across in addition to occasional veinlets of pyrite, pyrrhotite, galena and arsenopyrite. Iron and manganese staining is common on outcrops and in drill core.
Work in 1965, by Richfield Oil Corporation, indicated the north end of the stock contains 450,000 tonnes of 0.1 per cent beryllium oxide (Assessment Report 13415, p. 21). Diamond drilling in 1985 and 1986 by Lumberton Mines Ltd. encountered zones containing in excess of 1 per cent tourmaline (Assessment Report 15760, p. 12). Nineteen samples of feldspathic pegmatite analyzed as follows in per cent (Exploration in B.C. 1987, p. B111):
Tests carried out by CANMET indicate that the pegmatite can be
processed to produce feldspar and mica concentrates that meet
industry standards with full liberation at 50 mesh.
This stock was first staked in 1958 as a beryllium prospect.
Subsequent exploration, by various operators in the 1960's and by
Lumberton Mines Ltd., in 1984 and 1985 failed to discover beryllium
reserves of sufficient grade to warrant further development as a
beryllium prospect. However, this work combined with further
sampling and diamond drilling by Lumberton Mines in 1986 indicates
that the stock contains a considerable amount of glass and ceramic
The property is located on the east side of Hellroaring Creek
between the 1,219 and 1,524 metre elevations, 33.7 kilometres due
south of the east end of St. Mary Lake.
In 1958 H. Bennett of Cranbrook located the Linda and Linda No.
1 claims on a pegmatite showing in which he found beryl crystals.
International Beryllium Corporation was formed in 1961 to prospect
the property, which had been expanded to 32 claims. Some 1,219
metres of trenching was done before the project was abandoned.
The property was acquired by Canuck Beryllium Corporation and a
small amount of stripping and open-cutting was reported done by the
company in 1963. An agreement between Canuck Beryllium, a subsidiary
of Peace River Petroleum Ltd., and Richfield Oil Corporation of
California for prospecting and development work on the property was
announced in August 1, 1965. Under the terms of the agreement,
Richfield Oil will have control over operations. Work in 1965 was
limited to blasting and sampling some 365.7 metres of trench. This
work is reported to indicate 500,000 tons averaging 0.1 per cent
Beryllium oxide (Bearcat Explorations Ltd. News Release., 1/02/1984).
Some 4,550 acres of mineral claims covering these showings were
acquired in early 1984 by Bearcat Explorations Ltd. (80 per cent) and
Colt Exploration (Western) Ltd. (20 per cent). A joint venture
agreement that same year with Fairholme Development Ltd. and Barnwell
industries, Inc. provided financing for an initial stage of
exploration. Work carried out in 1984 by Lumberton Mines Limited,
Bearcats 100 per cent owned subsidiary, included trenching and 500 m
of diamond drilling in 7 HQ drill holes; subsequent joint venture
interests were: Colt (15 per cent), Fairholme (5 per cent), Barnwell
(25 per cent), Bearcat (55 per cent). Further work in 1985-86
included 2584 metres of diamond drilling in 29 holes, and bulk sample
This work delineated three surface areas with significant
high-grade ceramic feldspar; potential by-products are high-grade
mica, high-grade silica, and a minor amount of beryllium in the form
Surface prospecting by Chapleau Resources Ltd. in 2000
revealed a number of new untested outcrops of beryl-rich pegmatite.
The work is reported to have extended "the old Richfield zone south
for 500 metres and 500 metres east". Values high in beryllium and
rubidium are reported from grab samples taken by Chapleau (George
Cross Newsletter, August 1, 2000 (No. 147).