最高品質の天然スピネルは、これまで大規模な処理プロセスを逃れてきました​​が、いくつかの熱処理されたものが市販されています。 このレポートは、加熱スピネルの鑑別基準を設定します。

With the use of modern tools and technology, this article sheds light on the history and provenance of both the French Blue and the Hope diamonds.

In November 2008, the Bangkok laboratory was fortunate to have an opportunity to briefly examine seven stones that the client had faceted from this parcel.

New data are presented for demantoid from Val Malenco, Italy, as obtained by classical gemological methods.

非常に高い温度における二次的液体インクルージョン（「フィンガープリント」としても知られる）への影響および熱処理の看破におけるそれらの有用性について検討します。

During the past 25 years, the corundum market has been transformed from one of medium to high-priced gems to one that encompasses nearly all price ranges.

This article describes what is known about the Wittelsbach Blue since it was first reported in 1666, and the gemological information released to date on this diamond.

Since late 2007, rubies and sapphires have been mined by hand methods from both eluvial and primary deposits at Winza in central Tanzania.

This article discusses the history and ongoing development of GIA's color grading system, and explains how its laboratory applies it.

Seven Chocolate Pearls supplied by Ballerina Pearl Co. and 12 untreated Tahitian cultured pearls (for comparison) were exposed to conditions of consumer care and wear.

Aquamarine, Maxixe-type (irradiated) beryl, and two types of hydrothermally grown synthetic blue beryl currently available in the marketplace were investigated by classical gemological methods, chemical analysis, and UV-Vis-NIR and mid-IR spectroscopy.

The finest and rarest emeralds are sometimes said to have an optical effect called gota de aceite.

A new find of rose quartz from Madagascar contained some unusual inclusions.

Copper-bearing tourmaline from Mozambique was first recovered in 2001, but its Cu content was not recognized until 2003, and it was not widely sold with its Mozambique origin disclosed until 2005.

Napoléon Bonaparte gave an extraordinary diamond necklace to his empress, Marie-Louise, in 1811.

Melee-size yellow synthetic diamonds have recently been seen in the gem market, mostly as loose stones but sometimes set in jewelry.

High-quality CVD-grown diamonds, comparable in color and clarity to natural diamonds, can be identified using a combination of gemological and spectroscopic properties.

Commonly seen in HPHT-grown synthetic diamonds with a green component, nickel-related defects were identified for the first time in a type Ia natural diamond with a strong green component.

Farmers have experimented with bead nucleation, but until recently the methods tried did not produce the quantity or quality necessary for economic success.