GIA laboratory-grown diamond services include an overall quality assessment for laboratory-grown diamonds. The GIA assessments for laboratory-grown diamonds have a distinct format to fully ...

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) ...

Figure 1. These 20 completely non-nacreous pen pearls, from the group of 22 samples in this study, are set against a pen shell displaying both nacreous (left) and non-nacreous areas (right). Photo by ...

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Miners collect spinels from gravel at the end of a long day at Man Sin. Photo by Vincent Pardieu, © GIA. In the spring of 2001, I was studying gemology in Yangon ...

Since its introduction in the early 1950s, GIA’s D-to-Z scale has been used to color grade the overwhelming majority of colorless to light yellow gem-quality polished diamonds on which laboratory ...

Figure 1. The GIA 7 Pearl Value Factors system classifies pearls according to size, shape, color, luster, surface, nacre, and matching. Composite photo by GIA staff. Prized by many cultures throughout ...

这款 3.74 克拉 公主方形切工中等色调蓝色海蓝宝石由22 颗钻石环绕其周围。 这枚戒指是 Zoltan David（大卫·佐尔坦）的原创设计，已获得版权保护。 — Robert Weldon（罗伯特·韦尔登），由 Nancy's ...

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, ...

There is only one known commercial occurrence of gem-quality red beryl in the world: the Ruby Violet (or Red Beryl) mine in the Wah Wah Mountains of Beaver County, Utah. The beryl is found mostly ...

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 ...