The GIA Laboratory-Grown Diamond Report includes full quality assessment with a plotted clarity diagram. Color and clarity specification are described on the same scale as the GIA Diamond Grading ...

追溯至 20 世纪 90 年代，Castellani（卡斯特拉尼）制作的这条 19 世纪古董复兴风格的项链，饰有心形和棕榈叶形吊坠，坠于有隔珠的狐尾链上。这张项链元素的特写照片展示了项链的双绞线细节和造粒工艺。由 Frances Klein（弗朗西丝·克莱因）古董和珠宝商友情提供。

As a consumer, you will regularly encounter in the marketplace gems that have been treated to change their appearance. A topic that often comes up is whether a particular gemstone is or isn’t treated.

Figure 1. A single tourmaline fiber contains three distinct chemical zones, each recording the fluid composition at the time of growth. Between zones, fluids dissolved preexisting tourmaline to ...

This 5.30-carat emerald from Brazil has a slightly bluish green color. Courtesy John Parrish, courtesy African, Brazilian, Colombian Gems Incorporated. Emerald has many special qualities, but colored ...

Diamonds have a long history as beautiful objects of desire. In the first century AD, the Roman naturalist Pliny stated: “Diamond is the most valuable, not only of precious stones, but of all things ...

祖母绿用于首饰已有几个世纪的历史。 有了适当的保养，现代珠宝镶嵌的祖母绿同样可以代代相传。 — Color Masters 友情提供 硬度和韧度 莫氏硬度用以衡量宝石和矿物的硬度。 这些数字基于一种矿物可被其他物品划伤的相对难易程度得出。 但莫氏硬度并不完全 ...

This 146.10-carat peridot is in the collection of the Natural History Museum in London Peridot has always been associated with light. In fact, the Egyptians called it the “gem of the sun.” Some ...

Opal can range from 5 to 6.5 on the Mohs hardness scale. Hardness and toughness Gem and mineral hardness is measured on the Mohs scale. The numbers are based on the relative ease or difficulty with ...

Cultured pearls come in different sizes, shapes, and colors. Perhaps the best-loved gems of all time, pearls—both natural and modern cultured pearls—occur in a wide variety of colors. The most ...

GIA clients will continue to receive their grading results for any submissions through Report Check and Report Check Plus. The Report Results API will only effect GIA clients that would like to use ...

The unique beauty of gem sapphires from Kashmir has brought fame to a locality about which little has been reported in recent years. After an initial burst of activity 100 years ago, the production of ...