A response to the Summer 2017 Lab Note on CVD synthetic overgrowth on a natural diamond.

A diamond with a previously unseen clarity characteristic is seen in GIA’s Carlsbad lab.

Reports on the internal features and spectroscopic and trace-element analysis of sapphires reportedly from Badakhshan, Afghanistan.

Scientists and gem experts shared the latest research and studies on gemstones at the Geological Society of America annual meeting in Denver.

A report from the 75th Swiss Gemmological Society Conference and European Gemmological Symposium, held in Zermatt, Switzerland June 30–July 1, 2017.

A green step-cut synthetic specimen hosts inclusions that provide insight into its growth method.

High-quality amazonite currently available in the jewelry market is tested at GIA’s Carlsbad laboratory.

A devotional object in the baroque style is on a brief European tour through the new year.

The first example of a lead glass–filled black star sapphire examined at GIA’s New York laboratory.

The first sapphire with green lead-glass filling examined at GIA’s Carlsbad laboratory.

A type IIa color-treated diamond was graded as Fancy brown-pink under daylight conditions and Fancy purplish gray under incandescent lighting, a color change that resulted from HPHT annealing and irradiation.

Examination of a 59.88 ct irradiated yellow diamond, one of the largest irradiated diamonds identified by GIA.

An iridescent Japanese andradite contained an iridescent inclusion of andradite, creating an arresting optical phenomenon.

A rough colorless beryllonite showed an unusually sharp separation between two regions, caused by minute inclusions deposited during growth that prevented growth of the host mineral.