Gem News International Gems & Gemology, Spring 2019, Vol. 55, No. 1

Potentate’s Montana Sapphire Mine: An Interview with Warren Boyd

Rough Montana sapphires.
Figure 1. Rough Montana sapphires in a range of colors. Photo by Albert Salvato, courtesy of Potentate Mining.

The history of the American West is told in stories of frontiersmen seeking fortune in gold and other precious metals. It was serendipity when these intrepid adventurers arrived in western Montana and discovered strange, shiny pebbles—sapphires—while looking for gold. Little did they know the gem wealth they had uncovered with the sapphires, which were simply a nuisance to the gold miners at first. More than 100 years later, this legacy of mining is carried on by several small-scale miners across Montana, and with the arrival of Potentate Mining at the Rock Creek sapphire deposit. We had the chance to sit down in Tucson with Potentate’s director of marketing, Warren Boyd, for an update on their mining activities and their plans to find a place for Montana sapphires in the market.

Sapphire mining can be challenging in the rugged Montana terrain. Harsh winters limit the mining season to about six months a year, and even then water shortages can make mining difficult. The year 2017 saw extreme wildfires that forced the mine to be evacuated several times. Despite these challenges, 2018 was Potentate’s third year at full production, yielding more than 100 kg of rough sapphire each mining season. In 2018, the mine commissioned a new processing facility with a larger throughput, which will allow Potentate to process more gravel and produce more sapphires each year. The facility features a gold recovery circuit to recover the fine gold that is produced along with the sapphires. Potentate has also devoted significant resources to protect the beautiful wild areas in which they mine, and a strict rehabilitation program is in place. They are only allowed to disturb five acres at a time, and after rehabilitation there will be little evidence of their mining activities. A water clarifier has also been implemented to purify their processing waters. This is important to protect the pristine trout fishing streams in the area.

The sapphires come in a range of colors (see above), from fine deep blues to fancy yellows, oranges, and pinks, and there are very rare Montana rubies. Some stones come out of the ground with a fine natural color, but the bulk of the production requires heat treatment to bring out these colors. Less than 1% of the sapphires recovered will end up as faceted stones in the 2–6 ct range, with most of the production cutting stones from 0.25 to 0.99 ct. Some extremely large stones have been produced, however. In the last mining season, Potentate recovered a 64.14 ct rough sapphire, the largest gem-quality sapphire ever found in Montana.

Potentate first exhibited at the Tucson shows in 2018, with a booth in the AGTA GemFair. With mining activities proceeding at full speed, Potentate’s focus now is to create market awareness of their commercial-scale production of sapphires, which represents a reliable supply of stones. Their big challenge is not finding a market for their rare large stones, but moving large quantities of small and mid-sized stones. Potentate is building relationships with jewelry manufacturers that have the capacity to find a market for Montana sapphires in the 0.5 ct range. The main markets are in the United States and Canada, but Boyd has seen interest growing internationally as well. Social media has been an important tool for Potentate, and they have started exporting stones to clients in India, Hong Kong, Sri Lanka, and Europe. Montana sapphires have even found a substantial market in sapphire-producing countries such as Australia, where consumers might be looking for their unique pastel colors that are different from those sourced domestically. With their significant investments in mining infrastructure and a clear strategy for getting stones to the market, Potentate Mining could make a substantial impact in the story of Montana sapphires.

Potentate's Montana Sapphires

Aaron C. Palke is a senior research scientist at GIA in Carlsbad, California.