Gemmological Characterisation of Sapphires from Yogo Gulch, Montana
A look at the mining and distinguishing characteristics of this naturally vibrant blue sapphire.
“Jedi” Spinels in Mogok
Documents a series of visits to Myanmar in search of exceptionally bright pinkish red spinels possessing no dark tones.
Update on gemstone mining in Luc Yen, Vietnam
Explores the emergence of the Luc Yen area as a producer of corundum, spinel, tourmaline and other coloured stones.
Blue sapphires from the Baw Mar Mine in Mogok
Reports on the microscopic, chemical and spectroscopic features that differentiate the high-quality Baw Mar sapphire from “classic” gem-quality Burmese sapphire.
Sapphires from Antsiranana Province, Northern Madagascar | Gems & Gemology
Since 1996, large quantities of yellow to blue sapphires have been recovered from alluvial deposits derived from basaltic rocks in northern Madagascar.
Ruby and Sapphire from Jegdalek, Afghanistan
This study provides detailed mining and gemmological information on the Jegdalek deposit, in east-central Afghanistan, which is hosted by elongate beds of corundum-bearing marble.
Sapphire and Garnet from Kalalani, Tanga Province, Tanzania
Located just 3 km south of the famous Umba locality, the geologically similar Kalalani area hosts deposits of gem-quality sapphire.
Rubies and Fancy-Colour Sapphires from Nepal
Gem-quality rubies and fancy-colour sapphires have been recovered from dolomite marble lenses located high in the Himalayan mountains of east-central Nepal (Ganesh Himal).
Sapphires from the Andranondambo Region, Madagascar
Since 1993, large amounts of gem-quality sapphires from the Andranondambo region of southern Madagascar have entered the international gem market.
Sapphires from Southern Vietnam
Gem-quality blue to bluish green sapphires from basaltic terrains in southern provinces of Vietnam have been entering the gemstone market since the late 1980s.