Diamonds and other gemstones are weighed in metric carats: one carat is equal to 0.2 grams, about the same weight as a paperclip. (Don’t confuse carat with karat, as in “18K gold,” which refers to ...

In 1983, the Argyle mine was established as the first major diamond-mining operation in Australia. Almost immediately, it became the world’s largest source of diamonds in terms of the volume (carats) ...

This 10.12 ct Fancy Vivid yellow pear shape illustrates the effect a fancy shape can have on intensifying the color in a yellow diamond. - Courtesy the Scarselli Family Color In diamonds, rarity ...

Soon after it was first marketed in 1976, colorless cubic zirconia became the dominant diamond imitation, with current production of approximately 60 million carats per year. Although cubic zirconia ...

Vietnamese aquamarine is notable for its attractive color and well-formed crystals. Commercially significant deposits are known only from the Thuong Xuan District in Thanh Hoa Province, where the ...

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" ...

This sapphire from Kashmir has an intense velvety blue color. – Photo: Robert Weldon/GIA. Sapphire is one of the Big three of jewelry colored gemstones—the other two are ruby and emerald. A durable ...

Those born in January are lucky to have the beautiful and diverse garnet as their birthstone. Garnets are commonly red but also come in an extraordinary range of beautiful colors, including orange, ...

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 ...

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 ...

The Diamond and Diamond Grading eLearning course brings to life the skills needed to grade the color, clarity and cut of diamonds through video, graphics, images and text.