What is a Montana Sapphire?

Blue and Green Round Faceted Montana Sapphires with a block of text overlaid that reads "Gems Explained: Montana Sapphires"


Montana sapphires are one of my favorite gemstones to work with because I love their rich shades of blues and greens. The colors remind me of places close to my heart: views of the California coastline, the splendor of Michigan’s Great Lakes, and the bright blue shores of Lake Tahoe. My Aurora collection showcases these striking sapphires in solitaire settings with hand engravings to emphasize their glow.

Let’s learn a bit more about these gorgeous natural gems and why they make such a great stone choice for your jewelry.

A range of blue and green round faceted montana sapphires

Sapphire Basics

While best-known for its blue hues, sapphire comes in every color on the spectrum, except for red. Sapphire is a gem-quality variety of the mineral corundum, and when corundum is red, it’s actually a ruby.

In addition to the brilliant rainbow colors of sapphire, it’s also an incredibly strong stone. It’s given a hardness of 9 on the Mohs scale, meaning only a diamond or another sapphire can scratch its surface. This high level of durability makes it an excellent stone for jewelry pieces you wear every day and heirloom pieces you hope to pass down for generations.

Where Are Montana Sapphires Mined?

Just as their name implies, Montana sapphires are sapphires from the state of Montana. They are primarily mined from the western half of the state near the Missouri River, Dry Cottonwood Creek, Rock Creek, and the Yogo Gulch.

They were first discovered by gold rush prospectors in 1865 and initially discarded in their search for the precious metal. They later realized that these rough stones were the first gem-quality sapphires to be discovered in the United States! Sapphires are still being mined in Montana today, 150 years after their discovery, with high environmental and ethical standards.

Geometric Faceted Montana Sapphire gemsImage courtesy of Columbia Gem House

What Gives Them Their Color?

The Montana sapphires found in the Missouri River, Rock Creek, and Dry Cottonwood Creek deposits are known for their high-clarity hues ranging from pinks and oranges to blues and lavenders. The rich blue-green and incredible cornflower blue Montana sapphires are specific to the Yogo Gulch.

The Montana sapphires I tend to use in my collections range from bright denim blues to rich deep teals. I describe them as “Medium Denim” or “Dark Teal” referring to the industry’s color grade for gemstones. These terms help me source the right stone when you are in search of a specific shade.

A variety of faceted montana sapphires in different colors sit in front of colorful montana sapphire rough gems
Image courtesy of Columbia Gem House

Heat treating further enhances and develops the gem’s color by dissolving rutile, a titanium oxide mineral inclusion formed inside a growing sapphire. This treatment is a routine industry practice and mimics the natural process of heating that occurs in the Earth’s crust. It’s not the process of synthetic dyeing or surface-treating but rather an application of heat that allows the titanium within the rutile to diffuse with trace amounts of iron, resulting in a permanently enriched natural blue.

Medium Blue Montana sapphire faceted round gems

Image courtesy of Columbia Gem House

Sourcing Montana Sapphires

For Montana sapphires and all of my gems and metals, for that matter, I look for suppliers I can trust. They need to share my values of sustainability and transparency, as well as have respect for their community and the environment. My hope is that this standard provides you with some peace of mind, too.

Columbia Gem House supplies my Montana sapphires and is the author of Fair Trade Gems® Principles and Protocols. Their Montana sapphires are ​​Fair Trade Level 1, which they define as:

“[A stone that] can be traced to a specific mine, where we either mine ourselves or have formal agreements with the producer, in which all Fair Trade Gems® requirements for workers and environment have been met. We visit the mine regularly, legally export, and cut these gems ourselves.”

Teal Montana sapphire faceted round gems

image courtesy of Columbia Gem House

Why I Work With Montana Sapphires

They’re one of a kind! Montana sapphires combine so many of my favorite things about sparkling gemstones: rich hues, everyday-wear durability, heirloom quality, and a trusted source close to home.

Montana sapphires are an excellent choice for those looking for alternative-gemstone engagement rings. Their brilliant color varieties alone make them an ideal option for any gem enthusiast.

About the Author

As a long-time jewelry designer, I love the process of sculpting, engraving, and setting everything by hand. Through my exploration of texture-driven techniques and organic shapes, I hope you can feel my passionate energy and intention behind every piece.

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