Research Article Search Results
Zircon with Unusual Color-Change Behavior
The Carlsbad laboratory recently had the chance to examine a 4.60 ct cushion-cut zircon with truly unusual color behavior.
Laboratory-Grown Diamond with Internal Laser Markings
Hematite “Rose” Inclusion in Aquamarine
Recently, a 23.67 ct pear cabochon aquamarine with light greenish blue color and poor clarity was sent to the Taiwan Union Lab of Gem Research (TULAB) for identification.
Glass Imitation of Star Sapphire
Heat Treatment Effects on the Behavior of the 3161 cm–1 Feature in Low-Iron Metamorphic Yellow Sapphire
This study examines FTIR spectra of yellow sapphire heat treated in an oxidizing atmosphere to deepen its color.
Fura Gems’ Inaugural Ruby Sale
Fura Gems hosted its first sales event for rough Mozambican rubies in August and September 2021.
FTIR Observation on Sapphires Treated with Heat and Pressure
A study on heat with pressure treatment of blue sapphires reveals FTIR patterns associated with different iron concentrations.
Fossilized Shell Consisting of Emerald
HPHT-Processed Diamond with Counterfeit GIA Inscription
Careful comparison of two GIA reports reveals a fraudulent inscription on a laboratory-produced diamond presented as a natural.
Purple Gem Spinel from Vietnam and Afghanistan: Comparison of Trace Element Chemistry, Cause of Color, and Inclusions
Figure 1. The vivid colors seen in fine gem-quality spinel are derived from the mixing between multiple different chromophores in a range of ratios and concentrations, as in this fine 13.52 ct violetish purple spinel. Courtesy of the Dr. Edward J. Gübelin Collection. Photo by Robert Weldon/GIA.
First Identification of Sudoite in Caribbean Ceramic-Age Lapidary Craftsmanship
Extensive analysis of early beads and pendants from archaeological sites in the French islands of the Lesser Antilles identified the objects as sudoite, which has never before been documented in any lapidary production.
Persian Turquoise: The Ancient Treasure of Neyshabur
Reports on the geology, background, and current state of mining and production at Iran’s largest turquoise mine.




