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 ...

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 ...

Figure 1. The sparsely populated high desert of eastern Oregon is home to three localities producing natural copper-bearing labradorite feldspar. In this view of Lake County’s Dust Devil mine, the ...

Some natural opals, mostly from Ethiopia, show a macroscopic finger-like structure called a digit pattern. This pattern consists of vertical columns that are more or less parallel, separated by a ...

Those born in January are lucky to have the beautiful and diverse garnet as their birthstone. Garnets are commonly red but also come in an extraordinary range of beautiful colors, including orange, ...

Figure 1. Pleochroism in a 15 ct tanzanite, as seen with the unaided eye through the crown and the pavilion sides and ends. Photo by Wimon Manorotkul. In describing colored gemstones, the major ...

Nephrite jade with high market value and production potential from the Chinese city of Hechi, in Guangxi Province, was tested by standard gemological methods, polarizing microscopy, scanning electron ...

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.

This 3.28-carat Paraíba tourmaline's vivid violetish blue hue rivals the finest sapphires. Because of this tourmaline's rarity, its per-carat price is also likely to rival the price of fine sapphire.

The Graduate Jeweler diploma program is a hands-on experience that introduces students to the knowledge and skills required for a career in jewelry fabrication and repair. You will work with gemstones ...

Useful contact information if you’re looking for a professional to value your gem or jewelry item. GIA does not provide an appraised value for gemstones or jewelry. This service should be performed by ...

If you were born in February, your birthstone is amethyst – the purple variety of quartz that has captivated mankind for millennia. Its lilac to deep purple hues can be cut into many shapes and sizes, ...