Documents a trip to the renowned opal fields of Lightning Ridge, Koroit, Yowah, and Quilpie.

An inclusion outlined by minute graphite crystals within a diamond create an octahedral shape.

「G&G Brief」では、Gems & Gemology（宝石と宝石学）2015年冬号の概要を説明しています。

This type of pink pyrope garnet, believed to have been mined in Tanzania, shows a distinct color-change phenomenon resulting from its unique chemical composition.

Natural pearls of unusual size and unique appearance are retrieved from the west coast of Mexico and examined in GIA’s New York lab.

Microscopic and chemical analysis may provide clues to the original source of Montana’s alluvial sapphires and help distinguish them from sapphires with overlapping properties.

Examines the origin and nature of tarnish spots in high-purity gold and how they can be avoided.

A semi-baroque pearl with an unusual radial feature is submitted to the Bangkok lab for testing.

Archival research and gemological characterization reveal the true story of this 135.74 ct blue sapphire from the French crown jewels.

An unfamiliar rough fragment acquired from Madagascar may point toward a new source of grandidierite.

Rare material from Brazil features four-ray stars under point-source light.

Two blister pearls attached to a host shell believed to have fossilized during the later Pleistocene period and discovered in southeastern Kenya are studied.