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 ...

Two major issues related to emerald are origin determination and the presence and quantity of fillers. An emerald’s value depends in part on the quality of the stone and treatments applied, so ...

Laser sawing of diamonds is beginning to revolutionize the diamond-cutting industry. Not only does the laser saw offer savings in time and money, but it also enables the cutting of material virtually ...

CARLSBAD, California – December 11, 2024 – Recognizing the industry’s interest in more information about the nature of fillers in emeralds, GIA will offer filler identification with its emerald ...

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 ...

12月の誕生石からどれか一つを選ぶとしたら、タンザナイト、トルコ石、ジルコンのどれをお選びになりますか？青から青みがかった紫色のタンザナイト、濃い青から緑色のトルコ石、様々 ...

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.

GIA studied more than 400 important gemstones from the Gübelin Collection and is committed to sharing this repository of gemological information. This work is a valuable resource for all students, ...

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 ...

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.

Lapis lazuli might be dyed to improve its color and conceal any calcite inclusions. Lapis that hasn’t been dyed might be impregnated with wax or oil to improve color and luster. These treatments have ...

この17.53カラットのアメシストは、豊かな赤みがかったパープルを呈している。 - Lydia Dyer, スーパートリリオンカットアメシスト、John Dyer & Co提供 アメシストは、何世紀にもわたって最も ...