This large Australian light opal cabochon weighs 117.85 carats. Small play-of-color flashes of orange and green predominate in a pinfire pattern, with spots of a more muted blue over a grayish ...

Quartz crystals were valued by the ancient Egyptians as talismans with powers to prevent aging. - Bob Kammerling Rose quartz beads dating back to 7000 BC have been found in the area once known as ...

This faceted rose quartz briolette weighs 18.29 carats. Its pastel color is a lovely example of the soft pink this gem is known for. - Robert Weldon, courtesy The Greenwood Group The soft translucence ...

Reviews the advancements and major trends in laboratory-grown diamonds observed by GIA since 2007. Gemological and Trace Element Characteristics of Cassiterite from Yunling, China Examines gem-quality ...

Large quantities of rubies—both rough and faceted—from a commercially important new source in Myanmar (Burma) have been available on the Bangkok market since 1992. The ruby crystals from the Mong Hsu ...

Observations of Oval-, Pear-, and Marquise-Shaped Diamonds: Implications for Fancy Cut Grading Presents findings from observations of oval-, pear-, and marquise-shaped diamonds, laying the groundwork ...

The September birthstone is sapphire – a gem that’s been cherished for thousands of years. Although the term sapphire usually refers to the blue variety of corundum (ruby is the red variety), this ...

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 ...

Although various forms of paints and coatings intended to alter the color of diamond have likely been in use for almost as long as diamonds have been valued as gems, the modern era of diamond ...

This ancient necklace dates to 2000BCE. An inscription on the center stone is a South Arabian script from the 8th century BCE. - From "Gems and Gemstones: Timeless Natural Beauty of the Mineral World" ...

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供給するでしょう。 GIA ダイヤモンド オリジン レポート: 科学に ...

This course examines jewelry’s important features and how they combine to give a piece its unique value. Content includes the unique qualities of precious metals, how to describe them to customers, ...