Update on Rock Creek Sapphire Deposit
June 17, 2015
The Rock Creek district sapphire deposits occur in debris flow, colluvium and secondary alluvial deposits (figure 2). Although the bedrock for these deposits has not yet been defined, Potentate plans further geological mapping and geophysical surveys in the near future to uncover these sources.
To date, the rough sapphires recovered from the bulk sampling pits range in size from 0.25 ct to over 20 ct. Approximately 15% of this rough occurs naturally in marketable colours, including pink, orange, orange-pink, lavender, golden yellow, blue-green and green, and fine blue (figure 3). A substantial percentage of the remaining rough responds very well to heat treatment technologies that improve clarity and turn greenish and greyish rough into desirable colours such as blue, orange, yellow, pink and parti-colour.
The high-grade concentration of the sapphires recovered from the various test pits, and the substantial inferred rough sapphire resources on Gem Mountain, indicate that Potentate would be able to provide a long-term consistent supply of sapphire rough to the global market (figure 4). Potentate would be the only large-volume source for the Rock Creek sapphires. The company is developing a marketing strategy that would provide sustainable supply chain guarantees to their clients. These clients, including wholesale gemstone cutters, polishers and fine jewellery retailers, would in turn be able to provide guarantees of origin and the presence (or absence) of any heat treatment to their consumers.
About the Author
Warren Boyd is a geologist and gemmologist with Potentate Mining, LLC in Philipsburg, Montana.