Combination of Phenomena in Star and Cat’s-Eye Color-Change Sapphire
Both asterism and chatoyancy are observed in a color-change sapphire.
Spring 2022 Auction Highlights
Large near colorless, blue, and yellow diamonds broke auction records at Christie’s and Sotheby’s in the first half of 2022.
Yellow Sapphires with Unstable Color
A lab in Bangkok shares study on color stability in yellow sapphire.
Characteristics of Newly Discovered Amber from Phu Quoc, Vietnam
Offers the first detailed summary of amber from the Vietnamese island of Phu Quoc and a comparison with Baltic, Dominican, and Burmese material.
Natural Radioactivity in Select Serpentinite-Related Nephrite Samples: A Comparison with Dolomite-Related Nephrite
Uses gamma-ray spectrometry to directly measure internal radioactivity in green nephrite from deposits in Poland, Russia, Canada, and New Zealand.
The Shape of Ekanite
Discusses the unusual surface characteristics of ekanite from secondary deposits in Sri Lanka.
A Look at Diamonds and Diamond Mining in Guyana
Reports on diamonds from Guyana’s alluvial deposits, including mining history and practices.
A Gemological and Spectroscopic Study with Mobile Instruments of “Emeralds” from the Coronation Crown of Napoleon III
An examination of 45 gems from the coronation crown of Napoleon III, using nondestructive mobile spectroscopic and gemological testing methods.
Large Diamond Inclusion in Diamond
A fascinating diamond crystal inclusion displaying a transparent, ghost-like appearance is identified in a Faint green diamond.
Natural Diamond with Extensive Network of Etch Channels
Numerous etch channels are observed in a 5.19 ct type IIa natural diamond.
Brilliance Exhibit at the Natural History Museum of Los Angeles County
A glimpse at the rare gems recently on display at the Natural History Museum of Los Angeles County’s Brilliance: The Art and Science of Rare Jewels exhibit.
Inclusions in Gemstones
This installment of “Colored Stones Unearthed” explores inclusions in gems—how they form, how they are studied, and what they mean for gemologists and geoscientists.
Smithsonian’s Great American Diamonds Exhibit
Two impressive diamonds from Arkansas and Colorado are featured in the Great American Diamonds exhibit at the Smithsonian’s National Museum of Natural History.
The Big Find: Celebrating 50 Years of Maine Tourmaline
The historic discovery of a Maine tourmaline source is celebrated through jewelry designs featuring gems unearthed 50 years ago.
Unusual Cat’s-Eye Omphacite Fei Cui Jade
A unique jade cabochon with vivid green bodycolor and pronounced chatoyancy is examined at a lab in Shanghai.
A Large Aquamarine with Unusual Etch Features from Xinjiang, China
Unique natural etch pattern and dissolution cavities are observed in a large aquamarine crystal.
Diamonds from Guyana, Ekanite from Sri Lanka, a New Amber Source in Vietnam, and More...
An overview of the Summer 2022 Gems & Gemology content.
Unusual Glass-and-Quartz Triplet Imitation of Emerald
An extremely convincing imitation of emerald is examined in Beijing.
A Zircon with Strong Photochromic Effect
Photochromic zircon shows significant color change from medium light greenish blue to very dark yellowish green.
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