Triplite in Beryl

Orange crystal inclusion identified as the rare mineral triplite in a beryl from Pakistan.

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Reversible Twinning in Neodymium Pentaphosphate

Application of slight pressure perpendicular to the twinning planes reveals the unusual property of this synthetic gem.

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Solid Carved Dark Gray Diamond Ring

A ring made entirely of natural diamond was recently submitted to GIA’s New York laboratory.

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Diamond with Cavities Showing Radiation Evidence

Diamond formed at incredible depth shows evidence of radioactive fluids in cavities surrounded by green fluorescence halos.

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Phenomenon Resembling Play-of-Color in Sapphire

A phenomenon resembling play-of-color was seen in a 4.13 ct unheated sapphire recently examined by the author.

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Bismuth Glass-Filled Burmese Star Ruby

The Hong Kong laboratory recently examined a Burmese star ruby incorporating a significant amount of bismuth glass.

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Staurolite in Ruby

Conspicuous bright brownish red crystals in ruby matrix are the first recorded observations of staurolite in corundum.

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Quarterly Crystal: Unknown Inclusion in Triphane Spodumene

Afghani spodumene hosts an unidentified translucent orange crystal surrounded by an iridescent cleavage halo.

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History of the Chivor Emerald Mine, Part I (1880–1925): From Rediscovery to Early Production

Chronicles developments at the Chivor emerald mine in Colombia between 1880 and 1925, based on archival records.

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The Evolution of Chinese Jade Carving Craftsmanship

Explores the art form of jade carving in China across five periods from the late Neolithic Age to the present day.

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Rhodonite-Pyroxmangite from Tanatz Alp, Switzerland

Investigates the chemical, physical, and gemological properties of attractive rhodonite-rich rocks from this Swiss deposit.

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A Quantitative Description of the Causes of Color in Corundum

Presents a quantitative means of determining the causes of color in a gem material, using corundum’s six major chromophores as an illustration.

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Color Characteristics of Blue to Yellow Beryl from Multiple Origins

Discusses the features of alkali elements and their influence on the color of blue to yellow beryl.

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Formation of the “Matryoshka” Diamond from Siberia

A freely moving diamond crystal completely enclosed in a diamond from Siberia gets its name from the famous Russian nesting dolls.

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Diamond with Mobile Green Diamond Inclusion

Diamond inclusions are relatively common guests in diamond crystals.

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“Electronic Device” in an Atypical Bead Cultured Pearl

GIA’s Hong Kong laboratory looks at a new radio-frequency identification (RFID) technology for tracking cultured pearls.

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Trapiche Gems

The unusual six-rayed trapiche pattern, identified mainly with Muzo emeralds, has also been discovered in Mogok sapphires and Mong Hsu rubies.

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Fluorescence Spectroscopy for Colored Pearl Treatment Screening

A nondestructive rapid screening technique uses fluorescence spectroscopy to identify treated colored pearls.

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Russian Emerald

Untreated Russian emeralds, rarely seen in the market, demonstrate a range of color and degree of fineness.

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Nigerian Gems and Jewelry

Mina Stones promotes Nigerian gems including rubellite and sapphire as well as reviving traditional skills and symbols in the creation of original jewelry.

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