A look at the history of analytical instruments used for gem testing. UV-Vis-NIR spectroscopy measures how gemstones absorb and interact with light across the ultraviolet, visible, and near-infrared ...

You need access to the trusted data that appears on GIA grading and analysis reports in a reliable and secure manner. Customers today demand that the information they use to inform their purchasing ...

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 ...

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 ...

This ancient necklace dates to 2000BCE. An inscription on the center stone is a South Arabian script from the 8th century BCE. - From "Gems and Gemstones: Timeless Natural Beauty of the Mineral World" ...

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 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, ...

If you were born in the month of June, you are lucky enough to have three birthstones to call your own. June is one of only three months (the others are August and December) that has three birthstones ...

Kunzite’s beauty is apparent in both its natural crystal and faceted forms. - Robert Weldon Kunzite is the light pink to violetish purple variety of the mineral spodumene. It’s found in Afghanistan, ...

Figure 1. Two natural “horse conch” pearls and the shell from which they were reportedly extracted. Photo by Johnny Leung. Although GIA handles a wide range of pearls originating from different ...

"Chicken-blood" stone is one of the most prized ornamental materials in China, especially for use in elaborate carvings and seals. A fine-grained mixture of dickite/kaolinite and quartz, with varying ...

如果您出生于六月，那么您很幸运，可以拥有三种生日石。六月是仅有的三个有三种生日石的月份之一（另外两个月份是八月和十二月），让您有各种各样美丽的生日石可以选择。 六月生日石是珍珠、亚历山大变石和月光石。有这么多吸引人的选择，六月生日的 ...