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.
Rubies and Sapphires from Winza, Central Tanzania
Since late 2007, rubies and sapphires have been mined by hand methods from both eluvial and primary deposits at Winza in central Tanzania.
Gem Localities of the 2000s
The past decade saw some impressive discoveries of diamonds and coloured stones.
Sapphires from Thammannawa, Kataragama Area, Sri Lanka
The February 2012 discovery of high-quality blue sapphires at Thammannawa near Kataragama in south-eastern Sri Lanka has intensified gem mining and exploration in the surrounding area and all over the country.
Abstracts; Summer 2009
This article, from the Summer 2009 issue of Gems & Gemmology, is a compilation of abstracts of important gemmology-related articles published outside of Gems & Gemmology.
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.
Status of Ruby and Sapphire Mining in the Mogok Stone Tract
This article, based on two recent visits to Mogok, briefly reviews the mining history and geology of this extraordinary locality, and describes the current status of mining and the methods used to recover rubies and sapphires in the Mogok area.
The Yogo Sapphire Deposit
Yogo Gulch, discovered more than 100 years ago, is one of four major sapphire-producing areas in Montana, United States.
Rubies and Fancy Sapphires from Vietnam
Gem-quality rubies and pink to purple sapphires are being recovered from the Luc Yen and Quy Chau mining regions of Vietnam.