Yogo Montana Sapphires: Who, What, Where & Why

Here at The Natural Sapphire Company,we know a thing or two about Montana Sapphires:

A blue-green sapphire that, unsurprisingly, originate from the ground in the US State of Montana.

But have you ever heard of…Yogo Montana Sapphires?

Well done if your answer is yes, because they are one of the least helpful language known varieties of sapphires quickly becoming a hot topic. Although these sapphires are highly prized and have been much sought after in recent years, many of our customers and sapphire novices alike are a bit confused when it comes to the subject.

Blue-Montana-SapphireYogo Montana Blue Sapphires, are a type of sapphire that is only found in one specific location in Montana – The Yogo Gulch.

Although increasing numbers of people are becoming interested in Yogos, they remain something of a mystery with the public, emphasized by the common internet search for “Yogo vs Montana Sapphires”, technically Yogo sapphires come from Montana so they are the same thing.

We want to clear up the confusion. In this article we aim to provide you with an essential guide to  Montana sapphires.

Who Were The First To Discover Montana Sapphires?

At first the gold-rush prospectors of 1874 took little heed of the ‘blue pebbles’ they found while panning the Yogo Creek for gold. It wasn’t until 1895 that these pebbles were recognized to be sapphires! Shortly after this, in 1896 sapphire mining began in the Creek. The sapphires were more lucrative than the gold.  Controlling the mine at this time was Jack Hoover, a local rancher who had early on spotted the potential of sapphires.

In 1899, a trio of British businessmen purchased what was the New Mine Sapphire Syndicate for $100,000 (approximately $2.8 million as of 2015). At that point, the operation became unofficially known as the “English Mine”.

Old-Photo-of-miners-in-MontanaThis foreign ownership took place during World War 2; Montana sapphires were heavily mined during the war for their industrial abrasive and cutting purposes. However, because the Yogo mines were still owned by the English, the US government could not control their operations, so the mines were little affected by the war, even though industrial sapphires were critical to the war effort.

Yogo-MontanaIn recent years the mining capacity has dwindled, with the main mines being currently inactive since 2012. The main source of new Yogo sapphires are hobby miners operating on small tracts of land in the Creek. Yogo sapphires are not mined from the sand and gravel near river banks or alluvial deposits, but are deeply ingrained in igneous rock formations, making their recovery extremely difficult. Difficult and consequently costly and extremely rare.

Frequently Asked Questions

When it comes to Montana sapphires and Yogo Montana sapphires alike, there are a great variety of questions. Since they are still little known to the public here are some frequent questions we get.

Q:“What colors do Montana sapphires come in?”

A: Montana Sapphires most often come in green, lavender and most commonly blue-green. They have also been known to come in orange, yellow and pink colors but usually only when they have been heat treated.

Q: “What color is  ‘cornflower blue’ exactly?”

A:  ‘Cornflower Blue’ is the Yogo Montana sapphire’s trademark color, this alludes to their shade of medium-to-light blue containing little green. Montana sapphires mined out of the Yogo Gulch area can still have this mesmerizing color

Q: “How much do Montana sapphires cost?”

A:Prices for Montana sapphires vary, like all sapphires, depending on the the four C’s. Carat weight, Color, Clarity and quality of Cut. Since each stone is unique there is never a set price for a specific carat weight. The price is determined rather by the inclusions in the stone, the color and of course the quality and cut.Take a look at our Montana sapphires page to get an understanding of the price ranges.

Here are 2 examples  of pricing from our own collection:

certified-natural-untreated-montana-cushion-green-sapphire certified-natural-untreated-montana-oval-bluegreen-sapphire 

What Are Yogo Montana Sapphires? 

‘Yogo Sapphire’ is the preferred term for gems found in the Yogo Gulch, a Yogo is a type of Montana sapphire. Montana sapphires have incredible color and brilliance. The famous ‘cornflower blue’ color of the Yogo results from trace amounts of iron and titanium found in the bed-rock where they developed. Yogo sapphires are unique in that they are free of cavities and inclusions, and have high uniform clarity and even coloring.They maintain their brilliance in artificial light.

Consequently Yogos have no need for heat treatment to improve their appearance -They are perfect as they are; natural sapphires. With all these fantastic qualities it is not a surprise to discover that these sapphires are highly sought after.Interestingly, there are very few examples of particularly large Yogo sapphires being found – the largest recorded sapphire rough only weighed 19 carats (3.8 grams) and this came out of the ground in 1910.Because of their rarity, ‘large’ rough Yogo sapphire prices rise sharply when they are over 0.5 carats (0.10 g), and absolutely boom when they are over 1 carat in weight.


As has been stated that Yogo Montana sapphires are famous for their rich uniform cornflower blue color. However, a tiny proportion, 2%, are in fact purple and incredibly beautiful. ‘Montana Sapphires’ coming from all mines in Montana have a large array of colors from cornflower blue to lavender and green. When these sapphires are heated, yellow and orange are the most common results of this treatment. While these Montana sapphires may contain more inclusions than their Yogo counterparts, they are by no means, less beautiful. In fact, most Montana sapphires come in larger sizes than Yogos and the color range is larger, some of these stone are also inclusion free. Yogo sapphires are increasingly hard to find because the mines at Yogo Gulch have nearly stopped producing. Sapphires from other mines in Montana are easier to find but are still unique, being the only sapphires to be mined the USA.

Where Do Montana Sapphires Come From?

Antique Yogo Montana Map

Antique Yogo Montana Map

Yogo Sapphires are solely mined at Yogo Gulch in the Little Belt Mountains of Montana, although sapphires are mined elsewhere in the state.


Mine in Yogo Montana

Delmer L. Brown, a geological engineer and gemologist, surveyed the area in the late 1970s. He was able to identify the reasons for the unique characteristics of the Yogo sapphires based on their geological history. Most sapphires are formed under low pressure and temperature over short periods of time, and this is why most non-Yogo sapphires have imperfections and inconsistent coloring. Yogos, found at great depth, have been formed under immense pressure and for much longer periods, thus resulting in the creation of smoother and consistent stones.

Why Should I Buy A Montana Sapphire?

The incredible properties of Montana sapphires make them one of the most cherished and desired gemstones on the market – And rightly so. It would be hard to imagine a more beautiful jewel. Completely natural, rich deep consistent color, and absolute perfect clarity.

Montana sapphires come in many colors, their brilliance never dims, not even in the duller confines of artificial indoor light. Montana sapphires are therefore perhaps the most precious of sapphires.The US Geological Survey described them as ‘being among the world’s finest sapphires’. High praise indeed.sapphires possess amazing clarity and depth of color. This is why they are nearly always natural, there is nothing to be gained by treating them!

Montana sapphires possess amazing clarity and depth of color. This is why they are nearly always natural, there is nothing to be gained by treating them!


A display of our Montana Sapphires

I Want A Montana Sapphire!!!

Our Montana Sapphire selection consists of loose stones in various shapes, sizes,colors and prices. You can pick one and incorporate it in your own design or choose one of our unique ready made settings.Our Client Service advisers will be glad to assist you in creating the perfect item of jewelry. Take a look at our website under sapphires and find “Montana Sapphires”.