Description
Branko Deljanin (Gemmological Research Industries, Canada)
11pmPT (Vancouver) on November 18 (Tuesday), 2025
8am Paris, 11am Dubai, 6pm Sydney on November 19 (Wednesday)
Montana sapphires from both primary and secondary sources, are found as flattened tabular crystals, those from secondary sources show degrees of abrasion and rounded edges. When faceted most gems are cut as round brilliants and are less than one carat in weight, a two-carater gem would be extremely rare.
Yogo sapphires have a natural blue hue varying from faint to vivid in saturation, sometimes pink, purple and colour change stones are rarely recovered. Alluvial crystals from other deposits are mostly bluish green to greenish blue needing heat treatment to intensify the blue hue. Labs identify Yogo sapphires by their color, inclusions, lack of zoning, and UV-Vis-NIR spectra.
The 2nd BrankoGems International Gemmological Conference took place in Helena, Montana, featuring lectures on sapphire origins, workshops, and five days of field trips to major Montana sapphire deposits. Participants explored Yogo Gulch, Missouri River, and Rock Creek, gaining firsthand experience with both primary and secondary sapphire sources.
Join for a captivating journey through the amazing world of Montana sapphires with gemstone expert Branko Deljanin!
