The West Old & New Vol. III Issue I January 2014 | Page 12

Montana Sapphires
Yogo sapphires are a variety of corundum found only in Yogo Gulch, part of the Little Belt Mountains in Judith Basin County,
Montana, United States, on land once inhabited by the Piegan Blackfeet people.
Yogos are typically cornflower blue. They have high uniform clarity and maintain their brilliance under artificial light. Because Yogo sapphires occur within a vertically dipping resistive igneous dike, mining efforts have been sporadic and rarely profitable. It is estimated that at least 28 million carats of Yogos are still in the ground.
Jewelry containing Yogos was given to First Ladies Florence Harding and Bess Truman; in addition, many gems were sold in
Europe, though promoters' claims that Yogos are in the crown jewels of England or the engagement ring of Princess Diana are dubious. Today, several Yogo sapphires are part of the Smithsonian Institution's gem collection.
Yogo sapphires were not initially recognized or valued. Gold wa