Canadian Rockhound: Zeolites from the Kamloops Region of British Columbia

Zeolites are a group of related hydrous tectosilicate minerals, very popular among collectors, that occur in cavities of basic igneous rocks, especially vesicular basalt. They contain water in microscopic channels within a framework; the water can be driven off (by heat) or replaced without altering the structure of the zeolite minerals.

Chabazite and calcite. Chabazite is a popular zeolite mineral among collectors.

In Canada, zeolite specimens are known to occur in Nova Scotia, Québec and British Columbia. Nova Scotia is known for producing fine quality specimens of heulandite, chabazite, and stilbite. Mont Saint-Hilaire, Québec, famous for the variety and quality of its minerals produces large crystals of natrolite and very large analcime crystals. Analcime clusters with crystals as large as a snowball have been collected recently. In British Columbia, various zeolite species occur at several localities in the Kamloops region. Zeolites found include heulandite, chabazite, stilbite and many other species.

Listed below are some localities in the Kamloops region. I have named several of the different varieties of zeolites. When collecting these minerals, be patient. But do not be afraid to break some rocks, as these zeolites will not disappear on you. There are plenty to be found at these localities.

Town of Cache Creek

Natrolite, Analcime

Coarse natrolite needles, up to 9 mm long, with pyramidal terminations are found on colourless trapezohedra of analcime on the north side of the road following the (Cache) Creek, approximately 5 miles northeast of the town of Cache Creek. Further, up this road leads to the erionite locality in Pass Valley.

Gold Pan Camp, Spences Bridge, Fraser River Canyon, Cache Creek Regions:

Heulandite (pink), Laumontite, Chabazite, Epistilbite, Stilbite, Colmanite

White prisms of laumontite are found on quartz and pumpellyite at Spences Bridge, in the Fraser River Canyon. Colourless, transparent epistilbite crystals, up to 2 mm long, are rarely found at Gold Pan Camp, near Spences Bridge, but abundant pink heulandite crystals can be found directly across from the entrance to the park in the road cut.

Ferrierite.

Ferrierite.

Kamloops Lake Region:

Ferrierite, Chalcedony, Goethite, Calcite, Clinoptilolite

The railway cut on the north shore of Kamloops Lake, west of the city of Kamloops is still the best and most abundant locality in the world for Ferrierite. Ferrierite is abundant in weathered olivine basalt pillows and flow-breccia that extend for 1 km along the railway, on the hill above the railway cut, and along the shore of Kamloops Lake. Calcite-chalcedony-filled nodules are lined with small, red, radiating groups of ferrierite that may reach 8 cm to 25cm in diameter. Ferrierite commonly lines the walls of veins, up to 10 cm thick and 4 meters long, that are filled with an intergrowth of calcite and chalcedony. Rarely, geodes, up to 13 cm by 30 cm in diameter, are lined with ferrierite, covered by amethyst or clear quartz crystals, calcite crystals, and small, brown needles of Goethite. The largest crystals can reach 3 mm wide, 1 mm thick, and up to 15 mm long, forming large, colourless to cream-coloured aggregates, from 2 mm to over 3 cm in diameter. The cavities are coated by a light green clay, which is covered by an egg-shell-thin chalcedony layer that preceded radial groups and linings of bladed Ferrierite. Collecting is excellent and allowed – with the permission of Mr. Bob Campbell in Kamloops.

Chabazite vug.

Chabazite and stilbite.

Chabazite crystals.

Twig Creek, Monte Hills,
West of Monte Lake,
Kamloops Region:

Heulandite, Analcime, Levyne, Stilbite, Thomsonite, Paulingite with Erionite and Offretite
(Chabazite with micro Gypsum blades. Approx. 10 ft. up a 15 degree embankment. 7.0 km. on main road just past Twig Creek Rd. junction)

Small, 0.5 to 1 mm colourless to orange or red rhombic dodecahedral crystals of paulingite can be found on colourless to golden, hexagonal offretite-erionite prisms, terminated by a dominant pinacoid and small pyramids, lining vesicles in Tertiary basalt along a logging road near Twig Creek, Monte Hills, west of Monte Lake. Proceed west on a logging road that follows the north shore of the lake, up Monte Creek, and into the Twig Creek headwaters. Turn right at the 16 km marker and collect in the bank 100 yards from the intersection with the main logging road. Some zeolite-bearing rock containing chabazite and stilbite is exposed in the gutter along the road. Most of the specimens are dug from the loose dirt covered talus above the north side of the road, or from boulders on the other side of road. The paulingite commonly displays frosted, etched, or pitted faces. Some specimens have clay covering hollow dodecahedron-shaped cavities that were once paulingite. Colourless to light yellow, flat-topped stilbite crystals, up to 2 cm long, form attractive, parallel, bundle-like aggregates are associated with colourless rhombohedra of chabazite, up to 5 mm across, and small, colourless Heulandite crystals, up to 3 mm across.

Natrolite.

Prehnite.

Mesolite.

Monte Lake, Kamloops Region:

Ferrierite, Calcite, Goethite

Colourless, salmon-orange, and red, Mg-rich ferrierite is found in calcite filled vesicles and veins along the east side of Monte Lake in altered Middle Tertiary basalts and in railway cuts southeast of the lake. Calcite-filled ferrierite-lined nodules and veins, up to 8 inches across, are found in highly weathered basalt in a road cut along Highway 97 between Blue Fountain Campsite and the government campsite along Monte Lake. Additional calcite-filled nodules lined with beige coloured ferrierite are found in railway cuts south of Monte Lake just south of where the railway crosses Highway 97. Calcite co-crystallised with much of the ferrierite and interfered with its growth producing poorly formed crystals. Excellent free growing ferrierite blades, up to 8 mm long, associated with calcite crystals are found in cavities, up to 3 inches across, near the 3rd telephone pole south of a side road along the lake between the government camp and the railroad crossing. The best rock has fallen from 15 to 20 feet from a vesicular portion of a flow in the cliff. Much of the ferrierite is coloured very attractive shades of orange and red from iron oxides and make excellent specimens. Large chalcedony nodules and quartz geodes are present. A few pockets, up to 6 inches, are found in the cliffs along the railway southeast of the lake that contain exceptionally long, thin, free-growing ferrierite crystals, up to 3 inches long and only 1 mm wide.

Douglas Lake Road, Westwold,
Kamloops Region:

Chabazite, Thomsonite, Stilbite, Heulandite, Levyne, Offretite, Calcite, Mesolite, Cowlesite, Phillipsite, Goethite

Basalt talus slopes and cliffs along the Douglas Lake Road, 9 to 10 miles west of Westwold, contain levyne plates overgrown with, white, yellow, or orange, silky offretite needles, 2 to 3 mm long. The offretite covers the edges of the levyne to form simple appearing short, hexagonal prisms terminated by a broad, rough, basal pinacoid that is composed of thousands of offretite needles, all parallel to each other and to the c-axis of the tiny thin levyne plate buried inside. Found in nearby cavities are light-grey cowlesite blades (lining vesicles up to 10 cm in diameter), bladed thomsonite, rhombohedra of chabazite (small and colourless), radial aggregates of phillipsite crystals (brownish-tan to colourless), stilbite (up to 10 mm in diameter), heulandite, mesolite (thin, hairlike needles) and calcite.

It is hoped that this article has given you a better understanding of the small world of zeolites. There are many more zeolite locations in the Kamloops region of British Columbia. However, they are too numerous to mention here. If you want to know more about the localities mentioned, or others not mentioned, feel free to contact me anytime.

This article may not be copied, distributed or reprinted in any form without the author's permission. To contact the author, please use the e-mail address provided. If you are unable to contact the author, please contact the Canadian Rockhound. Authorized reprints must acknowledge the author and the Canadian Rockhound, and include the website URL address of the Canadian Rockhound.

In this Issue:

Introduction