Paul B. Downing
Reprinted from and article in Rock and Gem Magazine, 1991.
Reprinted with permission.
Precious opal from British Columbia? Impossible! Except that, as I write this, I hold a specimen in my hand which shows bright flashes of red, green and orange fire. This is the first recorded find of precious opal in British Columbia - or anywhere in Canada. It is beautiful.
The first strike was made on Canadian Thanksgiving Day, October 14, in 1991. Glen, Darryl and Carolyn Grywacheski were exploring the area of an earlier agate and common opal find, near Vernon, B.C. They were digging along a fault line when Carolyn found an opal with a peculiar green shine. Glen confirmed that it was precious opal. Of course, it became known as the "Thanksgiving Opal."
Several pieces of precious opal were found that day and more have been found since. Most were closely associated with a banded agate and common opal in white and honey colors. All the opal was found as seams and nodules in a variety of volcanic materials.
Further exploration has partially exposed the extend of the find. Precious opal covers an area at least 100 by 200 meters (roughly 300 by 600 feet). Full-scale exploration awaits the acquisition of power equipment.
This opal is fascinating. It is similar to Mexican opal in appearance, as the base color is mostly clear, orangish crystal. The fire is throughout the stone, again reminiscent of Mexican rough. However, the matrix is much softer than the Mexican rhyolite and will not polish or hold up as jewellery. All stones must be cut as solids, doublets or triplets without matrix.
The potential for cutting material is quite large, matched only by the variety of opal types found. The best opal consists of larger chunks of precious crystal opal which can be cut as cabochons or faceted. I have cut one attractive stone that could easily be confused with a Mexican opal. It has red multicolor fire in a light-yellow base. The opal has proven stable thus far. My hope is that more of this type of material will be found.
A second type of opal found on this hill will prove enjoyable to cut and wear. It is a transparent, amber-colored common opal which will cut excellent faceted stones. So far, this type is more frequent and larger than the pieces or precious opal. Other types of opal found include white, dendritic and hydrophane opal, with or without fire.
Glen, along with Bob Yorke-Hardy, has pegged the area. Bob asks everybody to refer to the material as British Columbia opal, not Canadian opal. Development is in the offing. I sure hope they find lots of this gorgeous stuff.
The new finds are very exciting. Perhaps North America will become a - or even the - major source of opal in the future.