The gemological properties of synthetic green and lavender jadeite, which has been manufactured by the General Electric Company on an experimental basis, are summarized. The synthetic jadeites ...

すべてのGIA拠点でご利用可能。 マラウイ産のブルージルコンが報告される マラウイで新たにブルージルコンの産出が報告されました。研磨すれば美しい宝石となる原石を宝石取引市場に ...

Consumers now, more than ever, have a heightened awareness of sustainably and ethically sourced products. The GIA Diamond Origin Report uses scientific evaluation to provide confirmation of a ...

Two dark brownish red faceted stones, recently submitted to the GIA Gem Trade Laboratory for standard origin-of-color reports, were found to be treated synthetic diamonds. This conclusion was based on ...

Pietersite has been described as a brecciated variety of tiger’s-eye. This study examined pietersite specimens from Namibia and China (the main sources) using powder X-ray diffraction, optical ...

クラリティに関するプロット図付きの完全な4Cの評価。セットされていないDからZのカラー範囲の天然カラー ダイヤモンドで、重量は0.15カラット以上のもののみにご利用いただけます。

Jade is one of the most misunderstood gemstones. It is actually two separate materials: jadeite and nephrite. Together, these materials have more simulants than most other gems. Thus, it is important ...

Vivid blue, green, and purple-to-violet cuprian elbaites, renowned in the gem trade as “Paraíba” tourmalines, continue to be recovered in small amounts from northeastern Brazil. Since the initial ...

Figure 1. This alexandrite cabochon appears brownish green in fluorescent light (left) and brownish purple in incandescent light (right). The cabochon shows chatoyancy under both forms of illumination ...

Although conventional wisdom has been that irradiation will not alter the color of garnets, exposure of some colorless to pale-hued African grossulars to either 60 Co or 137 Cs gamma rays turns them ...

A new synthetic emerald grown in Western Australia is now commercially available as faceted stones. Infrared spectra revealed the presence of water, thereby confirming that these synthetic emeralds ...

This 376.85-carat tourmaline was carved by O. Hansen, using the colors of the tourmaline as part of the design. - Chip Clark, courtesy Smithsonian Institution, National Museum of Natural History ...