American Mined Sapphires

Montana Majesty



September babies are amongst the luckiest on the birthstone chart with Sapphire as the gem of the month. And although we LOVE all sapphires, regardless of their region, this month we are dedicating this blog to the most ethically sourced and precious sapphire variety of today: Montana sapphires.

0.90ct Round Teal Montana Sapphire cut by Dan Canivet and untreated.

*0.90ct Round Teal Montana Sapphire cut by Dan Canivet and untreated. 

More about Montana Mining

Montana mined sapphires are, perhaps, the world’s rarest sapphires. Why, you may ask? Well to put it simply, the colors they exhibit are unlike that of sapphires mined anywhere else in the world. Also, faceted Montana sapphires above a carat let alone three carats are pretty hard to come by, unlike African or Australian sapphires which are often found in larger rough sizes. According to Jeff Hapeman, owner of Earth’s Treasury-  to this date, the largest gem quality raw  blue Montana sapphire found was of 30.84 carats. After personally faceting the rough himself, with a recovery of a whooping 39.50% (which let me tell you, is impressive), the lovely faceted blue Montana sapphire weighed in at 12.62 carats! This gorgeous blue sapphire was then named the “Montana Queen” and will be on display at the Los Angeles Natural History Museum sometime this year.  

In retrospect, the largest recorded gem quality sapphire rough in history has been of over 600 carats, according to a 1907 article in the Sri Lankan Morning Leader!! This monster sapphire from Sri Lanka was named the “Blue Giant of the Orient”. After faceting, the sapphire was weighed in at an incredible 486.52 carats! So, as you can see, sapphires mined in Montana are very special. Not only that, but they are 100% ethically and responsibly sourced gems. Not to mention, Montana sapphires are typically faceted by master precision gemstone cutters here in America. What you end up with are stunning one of a kind sapphires, each displaying their own unique character, in beautiful, perfectly proportional designs.

So where do Montana Sapphires come from? Montana hosts five locations known to be rich in sapphire deposits. The primary deposit is in the Yogo Gulch, where the finest blue sapphires have been found. Due to their fine quality, the price difference between Yogo sapphires and other sapphires found in Montana can be quite significant.  The Rock Creek area, also called Gem Mountain, is situated in the Sapphire Mountains of Montana and is abundant in small fancy colored sapphires. Alternatively, several relatively rich sapphire deposits are located in the vicinity of the Missouri River, northeast of Helena, Montana. Gold prospectors during the gold rush created dredges along gravel bars, in an attempt to capture gold flowed in by the river. This also trapped sapphires for future gem miners, eventually creating both the El Dorado Bar and the Spokane Bar mines. These river bars collect larger and cleaner sapphires than any other area. Lastly, the Dry Cottonwood Creek hosts another sapphire deposit. But due to the pale nature of the sapphires and their flat structures, they’re not usually suited for cutting, and so mining in the area has been limited to the efforts of hobbyists.

Do Montana sourced sapphires come in colors other than blue? The answer is YES! And actually, the majority of Montana sapphires are found in light greens and blues-greens. But fancy colors such as yellows, oranges, pinks, purples, greys, and whites are also abundant. Even reds, technically Montana rubies, surface now and then (although they are very, very rare). Many Montana sapphires are color-shifters, and some change color altogether. It is easy to see the color shift when you go from the outdoors into indoor lighting. In general, color-shift properties are indeed a rare occurrence in sapphire, so the fact that many Montana sapphires host this property is pretty special.

Are Montana Sapphires routinely treated? Due to the light-colored nature of a lot of Montana sapphire material, yes, Heat treatment has become pretty standardized. The permanent process of heating (standard procedure for all sapphires) intensifies their natural color, and can remove internal inclusions such as silk, creating clean, more eye-appealing gems. Because heat treatment has become an industry standard for all sapphire material, it is not uncommon, and does not affect value as much as people think. Alternatively, when sapphires have a natural deep saturation of color and are clean enough to not need treatment, they are considered a rarity, and this increases their value quite drastically. Many Yogo sapphires do not require treatment, and their intense blue saturations and superior clarity. And although Yogos are very much collector’s items, they are often used in engagement rings, as they are sought after as much as any fine quality diamond!

Want to know more?! We have plenty of Montana sapphires that we would love to "show-and-tell" at our Seattle Studio. Contact us to find out more!


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