Two near-colorless rounds, weighing 3.23 and 2.51 ct, were the largest CVD-grown synthetic diamonds GIA has examined.

A field expedition from GIA Bangkok explores a new ruby deposit and collects specimens for study.

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

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

A new type of African chalcedony with the trade name “Aquaprase” shows unique composition and attractive color.

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.

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

A report from the 34th IGC, held in Vilnius, Lithuania in August 2015.

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.

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

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

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

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

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

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

宝石のすべての専門家は、世界的な宝石製造の中心地であり、中国の急成長中の宝石とジュエリー業界のリーダー都市深セン市に精通しています。 GIAチームはこの街を見学し、その主要なジュエリーブランドの詳細を発見していきます。

オークションハウスは業界にとって困難な年であるにもかかわらず、輝かしい記録的な入札によって今年も成功を収めました。