Montana is the only state in the United States with any significant production of gem-quality sapphires. Sapphires have been known to occur in Montana for over 150 years and have been actively mined there for more than 100 years. So with them being mined locally in our country and for that period of time then why are they not more known and available?
It wasn’t until 1894, however, that they are recognized as valuable, when a sample of these beauties was sent to George Kunz at Tiffany’s in New York. What made these sapphires so remarkable was their intense blue and violet colors and extremely high clarity. The gems were clear and free of a lot of inclusions making them more desirable and more valuable.
In the 1890’s several other deposits of sapphires were located in Montana, all alluvial and all located while miners were looking for gold. The largest and most significant deposit is located in the aptly named Sapphire Mountains west of Butte in the upper Rock Creek drainage. These sapphires are abundant, but tend to be very small, averaging just over one carat in the rough. While they have high clarity, their high iron content means that most are a light green color and not the desirable blues. However, natural yellows, oranges, pinks and the occasional blues are found in this deposit. The Rock Creek deposit was mined from 1906 through 1943 for industrial uses such as abrasives and the jewels used in watch making. With the advent of inexpensive synthetic sapphire, this mining became uneconomical.
The original lamprophyre lava dike that was the source of the sapphires was located and subsequently mined from 1899 through roughly 1920, but production was low and the stones primarily small. Since that time there have been intermittent efforts at mining the Yogo sapphires.
There are four localities where sapphires are found in Montana, and only one of them is a primary deposit–the others are all alluvial deposits. These mines are small-scale operations with mining in the Missouri River area, Yogo in central Montana, Dry Cottonwood Creek in western Montana and at Rock Creek, popularly known as Gem Mountain. Sapphires from these regions generally are various shades of pastel colors. Bluish green and greenish blue are the most common hues but they may also be pink, purple, blue, green, yellow, gray and white (colorless).
Montana sapphires are an ideal choice if you’re looking for fair trade gems with ethical sourcing because they’re mined in the USA and have a transparent supply chain. All the companies mining in Montana have a commitment to protecting the environment. The miners follow state guidelines regarding water and land reclamation. For example, mining pits are refilled after reclamation, trees are planted and water is filtered and restored to potable levels.
The larger supplies of sapphires from Sri Lanka, Thailand and elsewhere have made significant mining of these gems uneconomical–at least on a large scale. Also, labor and mining costs in America cost so much more than the mining done in other countries.
Because of the ethical sourcing, we are seeing an increased interest in these lovely sapphires especially in bridal custom designs. How does one learn about Montana Sapphires being sold for jewelry? Perhaps our client has traveled in Montana and became aware of their existence and their limited availability. Once you have seen their bright but different blue and green hues that vary from common mined Sapphires, you will not forget how lovely they are. While some brides prefer to pair them with diamonds, we have also designed mixed color combos with the Montana Sapphires. We have made custom designed engagement rings either in traditional styling or more often in a more modern and unique design. (See photo below). We have also simply set them as traditional stud earrings.
This is a very interesting video about Montana Sapphire mining made by the Gemological Institute Of America (GIA) that you will enjoy.
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