Two cabochons displaying white four-rayed “stars” are fashioned from one large natural diamond crystal.

A graduate of GIA’s Hong Kong Jewelry Design program hopes her award-winning design will help raise environmental awareness.

An overview of how the gem and jewelry trade, from miners to manufacturers, and from designers to dealers, dealt with the many challenges posed by the pandemic.

Presents a method for accurately predicting the color of a gem material when viewed in any direction as long as the polarized spectra and the viewing angle relative to the c-axis are known.

Provides criteria for detecting the resin filling of turquoise, an advanced treatment that reduces porosity and can dramatically improve appearance and stability.

A rare chatoyant effect is produced within play-of-color patches in a natural opal.

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.

The GIA lab in Carlsbad recently had the opportunity to examine a truly “all-American” diamond.

Progress in creating laboratory-grown CVD diamonds allows for larger sizes, including the largest yet seen at the Carlsbad lab.

A holiday snowflake scene in a treated Mong Hsu ruby surprises and delights a gemologist in the Bangkok lab.

A parcel of small rubies was received for identification at the S Gemmological Institute (SGI) gem lab in Yangon, Myanmar.

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.

The annual Tucson Gem and Mineral Show has been a reliable source for the niche and the unusual, as seen with the rhodium-plated iron meteorites acquired by author BL at the 22nd Street Show in February 2020.

The Bangkok lab identified unexpected characteristics in a flux-grown synthetic sapphire.

Proposes a formation model for sapphire from the main deposits in southern Vietnam based on the chemical composition of their mineral inclusions.

A creative imitation using fused bluish green glass with copper platelets poses as Paraíba tourmaline.

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。

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.

GIA Johannesburg identifies fraudulent GIA inscriptions on several synthetic moissanites submitted as diamonds.