The soothing soft pink shades of rose quartz appeal to gem carvers and collectors. – Valerie Power, courtesy Arunashi People accept a certain amount of sand, dirt, and dust as ordinary ingredients in ...

Zircon became a December birthstone because it comes in blues similar to turquoise, the other birthstone for that month. Like January’s garnets and September’s sapphires, the variety of colors ...

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 ...

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, ...

Online courses and Lab classes required to earn your online credential offered via the GIA Online Division are listed below. Click here to download the requirements ...

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 ...

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.

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’s D-to-Z color grading system is based on the relative absence of color. GIA’s Fancy colored diamond color grading is based on the presence of color. GIA describes color in terms of hue (the color ...

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, ...

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 ...

单词琥珀色表示棕黄色，但琥珀（宝石）可为黄色、金色、白色、橙色至红褐色，甚至偏蓝或偏绿。 波罗的海琥珀一般比多明尼加的琥珀更加昂贵。 含有昆虫或植物内含物的琥珀价格比清澈无内含物的更高。 例如，没有昆虫内含物的凸圆面琥珀每件只能卖几 ...