Yogo sapphires are usually free of inclusions and their color is consistent throughout the whole stone. Once cut, the true beauty of these gems is released. They are often only found in very small sizes. The rarest of all colors will range from magenta to true red. Some will occasionally have a trace of purple color, and even more rarely, a strong violet hue. The vast majority come in a very fine cornflower blue. Yogo sapphires are a perfect blend of aluminum and oxygen with titanium titanium being responsible for the blue color. Initially, the early miners mined rock from wider veins that were up to 20 feet wide, but over time these veins were mined out.Ĭurrently, mining is limited to the narrow veins that are left, which are only 8-10 inches wide and 400 feet underground. These sapphires occur along a five-mile long strike in the earth. Today, they are only commercially mined deep underground. They were first found accidentally by gold prospectors in the 1880s, and eventually became the primary focus of mining in the area. These unique gems come from only a small place, named Yogo Gulch, located in the Little Belt Mountains of Montana. It’s the most precious sapphire found in North America and considered to be among the finest in the world. We’re going to Montana for a rare find and true natural wonder: the Yogo.

So what better gem to focus on for our special Gems by Geography series than the sapphire?īut, not just any sapphire.

We’ve learned that “Olympian Blue” is one of the hot colors for fall.