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 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.

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.

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.

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.

Historically, global rough diamond production has fluctuated greatly due to a myriad of causes, many of which are explored in this article.

Numerous natural-color colored diamonds from the Aurora Butterfly of Peace and other collections were studied using a new type of fluorescence spectrometer.

This article reviews the GIA Laboratory’s history of reporting on certain types of graining which are often the only characteristics present in large, high-clarity, high-color diamonds.

Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) is an important technique for quantitative chemical analysis.

Eight decades after the Cullinan diamond was mined, a team of gemologists examined the two famous gems that were created from it to become part of the Crown Jewels of England.

In early 2004, the GAAJ laboratory in Japan issued a lab alert about rubies they had seen that had large numbers of fractures filled with high-lead-content glass, which made them appear very transparent.

Treated cultured pearls with a “chocolate” coloration have entered the market from several sources.

Solid, vapor, and fluid inclusions in transparent gem rhodonite crystals from Broken Hill, New South Wales, Australia, have been identified for the first time using Raman spectroscopy and gemological/petrographic techniques.

Political upheavals and technological advances, as well as changes in social and governmental attitudes and initiatives, have produced major and ongoing changes in the diamond industry.

The Mt. Mica area in southwestern Maine has been mined for tourmaline and other pegmatite gems since the 1820s.