The Gujar Killi Emerald Deposit, Northwest Frontier Province, Pakistan
Over the last decade, Pakistan has developed into an important source for many gem materials. A number of localities have been identified for emeralds in particular.
A Historic Turquoise Jewelry Set Containing Fossilized Dentine (Odontolite) and Glass
Investigating a set of six antique brooches set with diamonds and light blue cabochons.
Gem-Quality Grossular-Andradite: A New Garnet from Mali
A find of new gem garnets has been made in contact metamorphic deposits in the Republic of Mali, western Africa.
Observations on GE-Processed Diamonds: A Photographic Record
Observations made at GIA on 858 GE-processed diamonds revealed several interesting features that may be diagnostic of this kind of diamond. Specifically, a significant percentage exhibited a slightly hazy appearance, noticeable internal graining, and other unusual internal features.
Copper-Bearing Tourmalines from New Deposits in Paraíba State, Brazil
Two new deposits of Cu-bearing tourmaline have been found in Paraíba State, Brazil, not far from the original source at Mina da Batalha.
Ruby and Sapphire from the Tan Huong-Truc Lau Area, Yen Bai Province, Northern Vietnam
Primary and secondary deposits in the Tan Huong–Truc Lau area of northern Vietnam’s Yen Bai Province have supplied rubies and some sapphires for more than a decade.
Tsavorite and Other Grossulars from Itrafo, Madagascar
Since 2002, tsavorite and other grossular varieties have been recovered from a primary deposit at Itrafo, a village in the Andrembesoa area of central Madagascar.
The Identification of Turquoise by Infrared Spectroscopy and X-Ray Powder Diffraction
Identifying Gem-Quality Synthetic Diamonds: An Update
Synthesized gem-quality diamonds from the General Electric Company are analyzed for characteristics that distinguish them from natural stones.
Inamori Synthetic Cat's-Eye Alexandrite
This article reports on a detailed gemological examination of this new synthetic cat's-eye alexandrite.
Gold-Plated Gold
The application of plating is detected on gold jewelry pieces in the Carlsbad laboratory.
Prismatic Zircon in Kashmir Sapphire
Elongated zircon inclusions display attractive birefringent interference colors in a blue sapphire from Kashmir.
Spring 2024 Auction Highlights
Several lots sold during the spring auction season far exceeded their presale estimates.
A Visit to Clarity Diamond’s CVD Facility
An in-depth look at Clarity Diamond’s CVD facility in Austin, Texas.
Multilayered Laboratory-Grown Diamond
A laboratory-grown diamond with multiple growth layers highlights the challenges of discerning the details of diamond synthesis.
Diffusion-Induced Blue Spinel-Like Layer on Natural Sapphire
Three natural sapphires exhibiting a surface layer of gahnite are studied at the GGTL laboratory.
In Memoriam: Jean Claude Michelou
The gem and jewelry industry mourns the loss of one of its true leaders.
A Large Multicolored Natural Blister Pearl
A large baroque-shaped blister pearl with a unique multicolored appearance is examined in the Mumbai laboratory.
Unique Moiré-Pattern Metallic Inclusion in Paraíba Tourmaline
An intriguing inclusion scene is analyzed in a Paraíba tourmaline from Brazil.
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