Two Australian rough diamonds demonstrate both pink and colorless sections in the same crystal.

An overview of the Spring 2021 Gems & Gemology content.

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 a visual guide to the internal features of natural, synthetic, and treated spinel, as well as inclusions of spinel in other gemstones.

Presents the internal characteristics of natural P. maxima pearls, obtained from real-time microradiography (RTX) and X-ray computed microtomography (µ-CT) analysis of 774 samples.

Oblique fiber-optic illumination of thin-film fluid inclusions in Brazilian aquamarine reveals a kaleidoscopic play of interference colors.

In a delightful juxtaposition, a diamond-shaped cloud inclusion appears in the center of a 0.53 ct round brilliant diamond.

Attractive iridescence creates a beautiful “play-of-color” effect on dendritic healed fissures in a blue sapphire.

The Carlsbad laboratory recently examined a Mexican opal containing a rare fluid inclusion with a freely moving gas bubble.

A singly-terminated topaz from Pakistan hosts a prominent phlogopite crystal with strong dichroism and lamellar cleavage planes.

The author examined a 0.56 ct Fancy grayish bluish green diamond with prominent green radiation stains.

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

CARLSBAD, Calif. – May 17, 2021 – GIA is seeing an increase in the number of laboratory-grown diamonds submitted for update or verification services with counterfeit inscriptions referencing GIA natural diamond reports.

CARLSBAD, Calif. – April 20, 2021 – Inspiration is a driving force in all of our lives, and it was the deciding factor in the difficult decision to select just two recipients for the Beyoncé Knowles-Carter x Lorraine Schwartz GIA Scholarship for full tuition to earn GIA’s Graduate Gemologist diploma through distance education.

CARLSBAD, Calif. – April 14, 2021 – Citing recognition of GIA for gemological report services and education, a Belgian court unequivocally ordered AIG Belgium, operating as American International Gemological Laboratories and Antwerp International Gemological Laboratories, to immediately cease using ‘AIG’ alone or in conjunction with other marks, or face significant penalty payments.

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

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 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.

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