Montana Sapphires: What Are They?

Nestled between the trees and rocky mountains of Missoula, Montana runs a 52-mile long river called Rock Creek. This river is known worldwide as a fly-fishing destination for its various types of trout, but the bed of Rock Creek contains even more valuable treasures - gold and sapphires. Located in the Sapphire Mountains of Montana, the Rock Creek Mine is one of the few sapphire mines in the United States, and one of the only mines in the U.S. to produce significant quantities of gem-quality sapphires. Truly, it's no wonder why Montana has been dubbed the "Treasure State" of the U.S.!

While sapphires have been and still are mined in places like Madagascar, Sri Lanka, Vietnam, Thailand, etc., Montana sapphires have been gaining a lot of attention in the jewelry world for their recognizable blue-green color and fantastic clarity. Add their exceptional durability, ethical and sustainable sourcing, and variety of other color options, and it's easy to see why they are taking the jewelry world by storm!

"Dusk" Purple & Orange Montana Sapphire

Our "Dusk" Mine Stone is a 1.57ct pear cut heated purple and orange Montana sapphire.

A History of Montana Sapphires - Discovery to Today

The year is 1865, and gold rushes are occurring all over the United States. Montana is a popular destination for gold mining, and prospectors scoured the rivers and creeks, panning through rock and silt hoping for shiny yellow nuggets. While M.H. Bryan was prospecting on the West Fork of the Rock Creek river, he noticed small blue and green pebbles in his pan. He collected a bottle full of these shiny pebbles and later gifted it to his grandchildren, joking that he had brought them home a bottle of "sapphires, rubies, and diamonds." It wasn't until these stones were sent to a jeweler later on that it was realized that these stones were, in fact, sapphires! Bryan and other prospectors returned to the beds and reported an abundance of the stones, although they were small and pale in color. Beginning in the early 1890's, these small yet abundant sapphires were mined and used for industrial purposes such as abrasives and for watch-making. Between 1900 and 1930, around sixty tons of sapphires were mined from this area. Soon after, the inexpensive flux method for creating synthetic sapphires took over, making the mining of these small Montana sapphires uneconomical. 

While the sapphires found in and around Rock Creek have very good clarity, they often come in more blue-green tones due to the high iron content of the area. The most desirable sapphires in the world typically have a deep royal blue color, and the green of Montana sapphires was once considered less desirable. In addition to that, the stones are often very pale in color rather than being rich and vivid, which is what jewelers and customers desired. Therefore, Montana sapphires were not originally used for fine jewelry purposes in commercial quantities.

"Judith" Blue-Green Montana Sapphire

Our "Judith" Mine Stone is a 1.53ct oval cut heated Montana sapphire that showcases a characteristic blue-green color that is common in Montana sapphires.

Fast forward to the late 1900's, and modern heat treatment processes and technologies for sapphires was gaining popularity. Heating sapphires allows the improvement of color and clarity in stones, and even pale stones can take on preferable fancy colors. Additionally, diamond-alternative gemstone options in wedding rings have been on the rise in recent years, and many customers are looking for a stone with unique coloring and/or other features. In 2011, Potentate Mining purchased 3,000 acres of this sapphire-bearing land, ushering in a new era of sapphire production for Montana. Now stones both small and large and in a variety of colors including blue, green, purple, pink, yellow, orange, etc. are mined and sold to the jewelry market. While many of these stones have been heat-treated, we often stock stones that feature their natural unheated color. Despite Montana sapphire mining increasing, the operations still remain small-scale and most rough stones are one carat or less, making these sapphires exceptionally rare and precious.

"Lady Di" Montana Sapphire Engagement Ring

This Princess Diana-inspired engagement ring features an incredible blue-green 3.4ct heated Montana sapphire.

Potentate Mine Mining Process 

Montana sapphires can typically be found in the alluvial deposits found along the Rock Creek river, and historically miners scoured the gullies and gulches of the area. However, Potentate Mining has had luck finding sapphires in the land between the gullies and hilltops as well. These areas often have large "mudflows," which are caused by large amounts of precipitation and rapid erosion. Mining involves sorting through the mudflow materials, sorting gravel pieces into three piles based on size: 

  • Gravel 1/8 inch to 1 inch = target material
  • Gravel <1/8 inch or less = stored for later processing, gold sluicing
  • Gravel >1 inch =  waste

Once the target material is sorted into a pile, it is moved to a washing facility. Material is washed using recycled groundwater from a nearby precipitation pond to clean it from clay and other debris. At this point, rough sapphire and even bits of gold can start to be seen in the material and it is picked through by hand. The resulting sapphires are sent to laboratories for further cleaning and are prepared to be heat-treated and sold to lapidary artists and jewelers around the world.

Rough Sapphires

One of the many reasons Montana sapphires are so great is that they are mined with sustainability and the environment in mind. After the mining and cleaning are completed, the mined areas are covered with materials from the local precipitation pond and are seeded with local grasses and plants that benefit the elk and other wildlife in the area. Sprinklers water the area until the plants have grown and the area is restored. Any other mining waste is used for local road paving. And because these stones are mined right here in the United States, you can have peace of mind that they are sourced ethically without unfair labor practices. 

Designing a Custom Montana Sapphire Ring

Sapphires are an excellent choice for rings and other jewelry for their exceptional hardness and toughness. Ranking a nine on the Moh's scale, it is one of the most durable gemstone options available falling behind only diamond and moissanite. This makes sapphire resistant to scratches, and its lack of defined cleavage means it's more resistant to chips and cracks; although, keep in mind that inclusions, especially surface-breaching inclusions can potentially make the stone more fragile. Sapphire can have exceptional longevity with proper care! To read more about sapphire hardness, care, and other general sapphire information read our September Birthstone Sapphire Blog here

The Staghead Mine is home to our hand-selected collection of ethically sourced, extremely unique and rare gemstones, which includes many Montana sapphires! Start by selecting your Montana sapphire from the Staghead Mine and work with our designers to customize or design from scratch your dream ring. We offer a wide variety of Montana sapphires in a variety of sizes, cuts, and colors. We even offer stones that are bi-color, tri-color, parti-color, color-change, and both heated and unheated specimens. Browse Montana sapphires and the other exceptional gemstones of the Staghead Mine here or start by checking out our collections of customizable ring designs here

Montana Sapphire Engagement Rings