The Yogo Sapphire Mine of Montana

Jake Hoover, a gold prospector, discovered “little blue pebbles” in nearby Yogo Creek back in 1894. Since that time the Yogo sapphire deposit has been mined by both open pit and underground methods. An English syndicate first mined the deposit, on a large scale, in the early 1900’s. That operation produced hundreds of thousands of carats of fine blue sapphire rough. In the later part of the 20th century other corporations, both large and small, have leased the mineral rights and undertaken sapphire mining with marginal success.

Weathered portions of the sapphire-containing dike material were being removed by trackhoe and hauled to a screening and washing plant for extraction of the gem sapphire. A guest of friends who owned digging rights on a portion of the dike. Most of the Yogo Gulch sapphire still mined from this deposit never reaches the commercial market. The gem rough is being collected by Sapphire Village residents who have digging rights on a portion of the dike. The sapphire they find is faceted locally and rarely makes its way beyond local jewelers and collectors. In 1984 a previously undeveloped section of the Yogo Gulch sapphire deposit was opened by the Vortex mining group.

The Yogo deposit was discovered back in the 19th century, and worked for several decades by an English company. As anyone who has seen one can testify, in sizes above one carat, Yogo stones are world class sapphires. Sadly, perhaps only one in 10,000 of the crystals that are found will cut stones above a carat. This has kept Yogo sapphires as an inside secret. Few are traded outside the country, with the lion’s share being gobbled up by collectors in the northwestern US.

In the 19th century, the famous Tiffany & Co. gemologist George F. Kunz was sent a cigar box of stones by the original miner, and the famous NY jeweler has remained a strong fan of the blue stones from Big Sky.

In 2005, Alaskan gold miner Mike Roberts was offered a trade. Lanny Perry owned the Vortex Sapphire Mine at Yogo Gulch, Montana and said he’d swap it straight across for Roberts’ gold mine outside of Fairbanks. “Why not?” thought Roberts. That’s how he came to own what is now known as the Roberts Yogo Sapphire Mine.

According to Roberts, Tiffany remained one of his biggest customers, but he just didn’t produce enough for their needs. Now, with Roberts’ death, it looks like Yogo sapphires could become even more scarce.