Pink-to-red coral has a long history as an ornamental gem material in jewelry, carvings, and sculptures. However, due to a variety of environmental and legal factors, the supply of high-quality, ...

Commercial quantities of gem-quality chrysoprase and green prase opal (nickel-bearing chalcedony and common opal, respectively) have been recovered from altered serpentinite deposits near Haneti, ...

Commercial quantities of gem-quality benitoite are known from a single location in the world, the Benitoite Gem mine in the New Idria district of San Benito County, California. A barium titanium ...

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 ...

The locality origin of natural-color blue sapphires from Kashmir can, in many cases, be positively identified. However, the field of origin determination is a very complex one – especially with the ...

CARLSBAD, California – January 14, 2025 - The Gemological Institute of America (GIA) has announced the planned retirement of its president and CEO, Susan Jacques, at the end of 2025. The Institute has ...

To address concerns about laboratory-grown and treated diamonds being mixed into parcels of melee, GIA has developed an automated system to analyze and sort melee-size diamonds quickly and accurately.

The GIA Diamond Grading Report includes an assessment of the 4Cs – Color, Clarity, Cut, and Carat Weight – along with a plotted diagram of its clarity characteristics and a graphic representation of ...

Diamond is available in a range of sizes and qualities to fit every consumer's tastes. One of the first things most people learn about diamonds is that not all diamonds are created equal. In fact, ...

标记每个晶体边缘的切口被称为重入角。 宝石爱好者通常将其形容为“白天的祖母绿，晚上的红宝石”，亚历山大变石是金绿玉矿物中非常罕见的变色类别。 它最初在 19 世纪 30 年代被发现于 ...

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 ...

GIA 研究宝石学家 Sindi Schloss（辛迪·施洛斯）是一位珠饰和全球饰品专家，担任 GIA 校友会凤凰城分会会长，最近在 GIA 卡尔斯巴德校区的一场讲座中发表了题为“异域资产：人类的宝石 — 具有 ...