Research News

An In-Depth Gemmological Study of Blue Sapphires from the Baw Mar Mine (Mogok, Myanmar)

Blue Sapphires
Rough and faceted blue sapphires from the Baw Mar mine in Mogok, Myanmar. Photo by Vincent Pardieu/GIA.

Myanmar (formerly Burma) is one of the world’s oldest sources of fine corundum. Over the last decade, the Baw Mar mine has increased its production, providing the market with a large number of fine blue sapphires. These sapphires have slightly different properties from the classic Mogok sapphires, but have not been studied in great depth.

Researchers from GIA’s Bangkok laboratory analysed 64 sapphire samples collected during field expeditions to Baw Mar. They investigated gemmological properties, inclusion scenes, spectroscopic features and trace element chemical composition. Results from their study and field observations from the mining area appear in a new article titled “An In-Depth Gemological Study of Blue Sapphires from the Baw Mar Mine (Mogok, Myanmar)”.

The sapphires were taken from different parts of the mine and exhibited different properties. The most striking difference is in the colour. Sapphires from the northern part of the mine showed a medium-to-dark blue colour, while those from the southern area were generally lighter in tone. Trace element concentrations were measured and compared with those from other metamorphic blue sapphire sources such as Sri Lanka and Madagascar.