History of the Chivor Emerald Mine, Part II (1924–1970): Between Insolvency and Viability
Many legends are told about the history of the Chivor emerald mine.
Separation of Natural from Laboratory-Grown Diamond Using Time-Gated Luminescence Imaging
Researchers from De Beers Group Technology present a technique that expands on the surface luminescence used in the DiamondView instrument to provide additional imaging information and quickly distinguish colorless or near-colorless natural diamond from laboratory-grown diamond.
Naturally Colored Yellow and Orange Gem Diamonds: The Nitrogen Factor
Presents the four major groups of defects responsible for the color in nearly all yellow and orange diamonds.
Hydrogen and Oxygen Stable Isotope Ratios of Dolomite-Related Nephrite: Relevance for Its Geographic Origin and Geological Significance
Examines the effectiveness of hydrogen and oxygen isotopes in discriminating dolomite-related nephrites from the four most important occurrences worldwide.
Optical Whitening and Brightening of Pearls: A Fluorescence Spectroscopy Study
Presents a study that suggests optically brightened pearls can be consistently separated from non-brightened pearls using fluorescence spectroscopy.
Purplish Pink Diaspore Reportedly from Afghanistan
Diaspore, an orthorhombic aluminum oxide hydroxide mineral with the formula AlO(OH), is a relative newcomer to the jewelry scene, with some stones possessing a captivating ability to change color between pale green, yellow, pink, and purple when viewed in different sources of light.
Finders, Keepers: Field Trip to Crater of Diamonds, USA
There’s only one place on earth where the general public can prospect for diamonds directly from a primary kimberlite pipe: Crater of Diamonds State Park.
Fossil Ivory Update with Lee Downey
Lee Downey, owner of Artifactual (Tucson, Arizona), spoke with us in early 2020 about his 35 years in the fossil ivory carving trade and the impact of ivory bans on his business.
Yellow and Orange Diamonds, New Identification Techniques, and the Chronicles of Chivor
Windmills in Rare Mineral Sphalerite
Whimsical windmill-like inclusions are found in a high-quality orange specimen of the rare mineral sphalerite.
Occurrence of Petrified Woods in the Russian Far East: Gemology and Origin
Scientists in Russia construct an origin story through the analysis of petrified wood popularly used in the souvenir trade.
The “Fragility of the Eternal” Kunzite: Origin, Cutting, and Identification
A master gem carver bases his latest design off a stunning stained glass window when attempting the world’s largest known cut kunzite.
Greenish Blue Glass Imitating Gem Silica
Gem silica, also known as “chrysocolla chalcedony,” is considered the most valuable variety of chalcedony.
Multiple Radiation Stains Suggest Interesting Geological Residency
A rough diamond crystal weighing 4.05 ct was observed with radiation staining on its surface.
Fluorophlogopite in Burmese Spinel
Lotus Gemology in Bangkok received a large parcel of dark red spinels for identification.
A Sapphire with a Negative Crystal Containing a Mobile Graphite Daughter Crystal
Mineral and fluid phases within negative crystals in metamorphic sapphires provide us with general information on the sapphire and the trapped fluid itself.
Böhmite in Corundum
Rubies from Mozambique, which were examined at the Lotus Gemology lab in Bangkok, proved to be infilled with böhmite, a secondary mineral in corundum.
HPHT-Processed CVD Laboratory-Grown Diamonds with Low Color Grades
Summer 2020 G&G Publication Information
This document provides the publication information for Gems & Gemology
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