A detailed characterization of serpentine from this mountain locality, focusing on its use as a gem material.

Presents the underlying physics and methodology of this analytical technique, which has become an essential tool in identifying treated and synthetic diamonds.

A look at the gemological properties and chemical composition of this light blue to light green to green gem material, which is suitable for cabochon cutting.

A synthetic spinel has undergone quench-cracking treatment, possibly to make it appear as a natural specimen.

A look at the resumed operations and new production of Kenya’s Scorpion tsavorite mine.

An overview of the 2016 gem shows.

Lesser-known gem materials are seen in pieces alongside a collection created as an artistic inheritance for future generations of jewelry fans.

A report on the HPHT growth of large, gem-quality colorless synthetic diamonds in China.

Lazulite crystals grow on and within a quartz specimen from Yukon Territory, Canada.

A round-cut specimen set in a ring is the first mounted CVD synthetic melee diamond identified by GIA.

Analysis of a 5.03 ct HPHT-grown blue synthetic diamond, the largest ever examined by GIA.

A parcel revealed to contain natural, treated, and synthetic diamonds reinforces the importance of identification.

An unusual doublet consisting of two sections of natural emerald is examined the Tokyo lab.

An emerging corundum deposit in northeastern China is discussed.

A rare spinel, featuring a Star of David pattern and multiphase inclusions, is examined in Bangkok.

The gemological properties of the first documented occurrence of red cordierite, from Madagascar, are examined.

Optical properties in a taaffeeite are explored.

一块帝王黄玉原石被雕刻成一颗精美的自由形态宝石。

A recent rush in Madagascar yields new sapphire production.

An opal rough is immersed in water and treated with oil and Opticon to observe effects on transparency and play-of-color.