This 7.19-carat alexandrite was cut to feature its beautiful color change. When the light source changes from daylight to incandescent light, the gem’s color changes from bluish green to reddish ...

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 ...

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 ...

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, ...

Jadeite comes in a wide range of colors. The most valuable is an intense green called Imperial. - Courtesy Mason-Kay Fine Jade Jewelry To understand the value of jade, you have to look beyond its ...

This jadeite "Peiyao" (Chinese Fu dog) represent mythological creatures that guard and protect celestial palaces and entrances. - Gift of Sophie Leu Jade has been cherished for thousands of years.

合成宝石材料是在实验室中制成的一种材料，但却具有与其相对应的天然矿物相同的化学、光学和物理特性，虽然在某些情况下，如合成土耳其石和合成蛋白石，可能会有其他化合物的存在。 自 19 世纪后期以来，就已经开始生产合成宝石晶体，其产品往往是 ...

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.

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 ...

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 ...

加利福尼亚州卡尔斯巴德 – 2020 年 7 月 27 日 – GIA，世界领先的独立钻石鉴定和分级权威；IBM 研究院，世界最大且最具影响力的企业研究实验室之一，二者强强联手开发先进的人工智能 (AI) 系统，力图为钻石净度分级带来变革。 GIA 的 AI 净度系统以 GIA 公认的 ...

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 ...