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Sapphire from Helena, Montana (El Dorado Bar) |
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Most Americans don't realize that exquisite sapphires have long
been mined from gravel bars and intrusive dikes in the state of Montana. There are
several reasons for this. First, the color of most of these stones isn't the typical
deep blue of stones from Sri Lanka, Myanmar, or Australia. Second, although there
has always been the potential for large-volume mining, the Montana localities have
rarely been exploited on a large scale (Perhaps because of the cost of labor in this
country).
Whatever the reasons, Montana produces sapphires as fine as any in the world. Not
far from Utica, Montana, a sapphire-producing lamproite dike cuts through the country
rock for almost five miles. Discovered by a prospector, Jake Hoover, in 1895, the
Yogo Gulch mine went on to produce hundreds of thousands of carats of exquisitely-clean
blue gemstones
But Montana has many sapphire locations. Most are alluvial deposits such as those
along the Missouri River near
Helena, or Dry Cottonwood Creek near Butte. Currently,
the largest sapphire production is coming from the Gem Mountain area near Philipsburg.
The Gem Mountain stones display a remarkable range of colors including blue, green,
pink, and gorgeous yellows and oranges. Further stimulating the sapphire "boom"
in Montana is the application of advanced heat-treating technology that can remarkably
improve the clarity and color of many Montana stones (Don't get upset: heat treatment
has long been a standard practice in Thailand to turn ugly Sri Lankan gueda sapphire
into fine blue gem material. Consult "Gems
and Precious Stones" in our links section to
learn more about gemstone treatments).
In the past, many of the Montana mines have been open to amateur collectors on a
fee basis, and many fine stones were found. Unfortunately, because so few of these
stones have reached the American jewelry market, many Americans feel these stones
aren't true sapphires or are somehow inferior to gems from the orient. The beauty
of these stones will eventually dispel that misconception.