Large “Rainbow Calcite”
CVD Laboratory-Grown Gem Diamonds from Plasmability
A report from the New York laboratory on colorless and near-colorless CVD gem diamonds produced by the Texas-based company Plasmability.
“Hummingbird” in Orangy Yellow Diamond
An omphacite inclusion surrounded by fractures in an orangy yellow diamond takes the shape of a hummingbird.
CVD-Grown Diamond with an Unusual Blue Band
An HPHT-treated CVD-grown diamond displaying a blue growth band is examined in the Mumbai laboratory.
New Nigerian Green Beryl Find
Vendors in Tucson exhibited Nigerian green beryl with concentrated color zones.
Copper in Indonesian Chalcedony
Examination of two chalcedony cabochons from a new source in Indonesia reveals an abundance of native copper.
Checkered Pattern on Diamond
The Mumbai laboratory examines a modified pear portrait-cut natural diamond.
Aquamarine with Fluorite Inclusions
A large aquamarine crystal from Pakistan displays multiple eye-visible fluorite inclusions.
Emeralds in Catherine de’ Medici’s Pendant: An Unexpected Geographic Origin
Archival research and gemological characterization reveal the geographic origin of two emeralds set in a pendant linked to Catherine de’ Medici, Queen of France from 1547 to 1559.
The 3309 cm^–1^ Series in Sapphire and Ruby: A Focus on FTIR Peak Position Variation
Investigates the correlations between peak positions in the 3309 cm–1 series with trace element concentrations for ruby, metamorphic and basalt-related blue sapphire, and laboratory-grown sapphire.
Heated Corundum, the Remarkable Winston Red, and an Extraordinary Renaissance Jewel
An overview of the Spring 2025 Gems & Gemology content.
“Enhydro” Amethyst from Morocco
A rare find of Moroccan amethyst with eye-visible fluid inclusions is spotted at the Pueblo show.
In Memoriam: Henry A. Hänni
The life of renowned Swiss gemologist and educator Henry A. Hänni is remembered.
Rare Gem-Quality Viitaniemiite
A Study of the Winston Red: The Smithsonian’s New Fancy Red Diamond
Presents the first scientific and historical study conducted on the 2.33 ct Winston Red, the fifth-largest known Fancy red diamond in existence.
Surfite: A Surfboard Manufacturing Byproduct
Crystal inclusions in a natural diamond resemble a unique scene.