Guardians of Trust: GIA’s Innovative Research, Instruments and Services
GIA’s services and instruments have grown in importance and impact as new gem treatments and laboratory-grown gems have entered the market.
Photoluminescence Spectra of Emeralds from Colombia, Afghanistan and Zambia
Compares PL spectroscopy data of 48 emerald samples from three countries to evaluate the usefulness of the technique in geographic origin determination.
Colombian Emerald Mining: Will the Giant Awaken?
Overview and commentary on the 2013 The Journal of Gemmology article “Peñas Blancas: An Historic Colombian Emerald Mine".
Unusual Curved Colour Zoning In Emerald
A report on a 1.17 ct emerald obtained in Kabul, Afghanistan for GIA's permanent reference collection
On the Identification of Various Emerald Filling Substances
Criteria for distinguishing emerald filling substances were investigated.
Emeralds from the Mananjary Region, Madagascar: Internal Features
Mananjary emeralds usually can be separated from emeralds from other localities by means of associations of certain mineral inclusions.
Emeralds from the Ural Mountains, USSR
Emeralds are again being mined in the historic district of the Ural Mountains. Physical, chemical, spectroscopic and microscopic characteristics of stones from the recent production are presented and compared with data on older samples as well as those reported in the literature.
Fracture Filling of Emeralds Opticon and Traditional "Oils"
The filling of surface-reaching breaks in emeralds is a relatively common practice, for which various kinds of oils and a natural resin have historically been used.
Emeralds of the Panjshir Valley, Afghanistan
With the withdrawal of Soviet troops from Afghanistan, villagers in the Panjshir Valley are turning their attention to the emerald riches of the nearby Hindu Kush Mountains.
Spring 1991 G&G Lab Notes
This section, from the Spring 1991 issue of Gems & Gemmology, is a compilation of interesting finds from GIA’s laboratories.