Large Type IIa Diamond from Arkansas, USA
The GIA lab in Carlsbad recently had the opportunity to examine a truly “all-American” diamond.
Fluorescence Characteristics of Blue Amber from the Dominican Republic, Mexico, and Myanmar
Presents a combination of observational and spectroscopic means to separate the three main geographic localities for blue amber, which shows very strong blue fluorescence under sunlight or D65 illumination.
Unusual Absorption in a Blue Flux-Grown Synthetic Sapphire
The Bangkok lab identified unexpected characteristics in a flux-grown synthetic sapphire.
Uncommon Inclusion of Lazurite in Ruby from Mogok, Myanmar
A parcel of small rubies was received for identification at the S Gemmological Institute (SGI) gem lab in Yangon, Myanmar.
Baroque-Era Rose Cuts of Colored Stones: Highlights from the Second Half of the Seventeenth Century
Offers a systematic evaluation of rose cuts produced for various colored stones in the latter seventeenth century, based on the examination of rare artifacts that belonged to the archbishops and prince-electors of Trier and Cologne.
A Study on Improving the Surface Appearance of Low-Quality Pinctada maxima Bead Cultured Pearl
白蝶貝から採取された低品質の有核養殖真珠の表面の外観の改善に関する研究
本研究では、バンコクのラボラトリーが、現地の真珠養殖場から直接採取された5つの低品質の有核養殖真珠を検査し、加工の前後の特徴を記録しました。
A Review of Analytical Methods Used in Geographic Origin Determination of Gemstones (英語)
Geographic origin determination relies on a combination of gemological observations and advanced analytical tools. This contribution reviews the analytical methods commonly used to establish origin.
Vietnam: Shell Nuclei, Pearl Hatcheries, and Pearl Farming
Reports on a visit to a shell nucleus manufacturer and two pearl farms in northern Vietnam, which is emerging as a notable producer.
A History of European Royal Jewel Sales, Including Sotheby’s 2018 Auction of Marie Antoinette’s Jewels
Chronicles important auctions of jewels from European royal collections over the years, with a focus on a recent high-profile sale of items that once belonged to Marie Antoinette.
Unique Raindrop Pattern of Turquoise from Hubei, China
Presents spectroscopic and chemical analysis of a new variety of turquoise with a rare raindrop pattern with saturated colors.
Inclusion and Trace Element Characteristics of Emeralds from Swat Valley, Pakistan
Presents a detailed study of gemological properties, inclusion features, spectroscopic characteristics, and chemical composition of emeralds from this important source.