In recent years, significant amounts of gem-quality sodalite/hackmanite—some unusually transparent—have been produced from the Mogok region of Myanmar and Badakhshan Province in Afghanistan. Samples ...

The cutter took full advantage of this iolite’s color and transparency, fashioning it into a uniquely carved gem, ready for use in jewelry. – Lydia Dyer, Gem courtesy John Dyer & Co. Affordable and ...

Although Afghanistan has historically been well known for its lapis lazuli deposits, significant amounts of fine emerald, tourmaline, kunzite, and some rubies are now emerging from that embattled ...

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 ...

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 ...

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 ...

For over 200 years, the only known source of imperial topaz has been a small mining district near Ouro Preto. One of the oldest and most productive mines in the district is the Capão do Lana. This ...

Experimental saltwater cultured pearls produced after xenotransplantation between P. margaritifera and P. maxima were studied using UV-Vis-NIR and PL spectroscopy as well as radiography. The results ...

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 ...

A hand-held flashlight reveals the green color of a rough emerald from the Coscuez Emerald mine in Colombia. Photo by Eric Welch/GIA. Emerald is the green to bluish green variety of beryl, a mineral ...

Fine-color, large, and eye-clean (lacking visible inclusions) rubies like this 11.01carat (ct) stone from Myanmar (formerly known as Burma) are extremely rare and valuable. – Photo: Robert Weldon/GIA.

Jadeite comes in a wide range of colors. The most valuable is an intense green called Imperial. - Courtesy Mason-Kay Fine Jade Jewelry To understand the value of jade, you have to look beyond its ...