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
A Review of Analytical Methods Used in Geographic Origin Determination of Gemstones (英语)
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.