Montana Sapphires vs. Yogo Sapphires - What's The Difference?

September 17, 2018

Our gift store features jewelry made with real sapphire stones mined in Montana. Montana is a special place for sapphires, because the stones mined here are unique, and our state produces more gem-quality sapphires than anywhere else in North America.

The term ‘Yogo’ refers to the Yogo Gulch in the Little Belt Mountains, east of Great Falls. This is the only place in the world where true Yogo Sapphires have been found. They are noted for their striking cornflower blue color, high uniform clarity and maintaining their brilliance under artificial light.

‘Montana sapphires’ refer more generally to sapphires that are mined anywhere else in Montana. While the color of Yogo Sapphires is always a vivid blue, Montana sapphires are found with different colors including green and yellow.

While there are productive sapphire mines in other parts of Montana, they rarely produce blue sapphires that have the striking color and clarity of those found in the Yogo Gulch.

Often times, Montana sapphires (and other sapphires found in other parts of the world) are heat-treated to enhance an otherwise dull blue color. That is why it is important to verify the authenticity of yogo sapphires as being genuine and untreated.  

While it is estimated that 5.6 tons (or 28 million carats) of Yogo Sapphires are still in the ground, the excavation of them is costly and difficult, which keeps their scarcity and relative price high.

The U.S. Geological Survey and many gem experts have stated that Yogos are “among the world’s finest sapphires”. The rough stones tend to be small and flat, so less than 10% of cut pieces end up being more than one carat in size.

Because of this, the price of Yogos increases sharply after 0.5 carats. Anything in the neighborhood of 1 carat or above will be very expensive.

Learn more about the history of Yogo and Montana Sapphires:

 Check out our collection of sapphire jewelry.


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