Established in 1931, the Gemological Institute of America (GIA) is the world’s foremost authority on diamonds, colored stones, and pearls. A public benefit, nonprofit institute, GIA is the leading ...

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 ...

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 ...

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 ...

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 ...

However gem quality diamonds are fashioned from the original crystal shape they possess a combination of brightness, sparkle, fire, and sense of purity not matched by other gems. - Jeff Scovil, ...

People from all over the world send their diamonds to the GIA laboratory for grading and analysis. Our clients put their business in our hands and their trust in our expertise – and we are extremely ...

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 ...

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 ...

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.

A synthetic gem material is one that is made in a laboratory, but which shares virtually all chemical, optical, and physical characteristics of its natural mineral counterpart, though in some cases, ...

Because laboratory-grown diamonds are essentially chemically and optically the same as natural diamonds, traditional gemological observations and instrumentation are not able to tell them apart. GIA ...