GIA is a trusted authority known for its rigorous, objective analysis of both natural and cultured pearls. Learn about how ...

Below is the list of recognized holidays when GIA locations will be closed.View the holiday schedule for all GIA locations worldwide.

Figure 1. The De Beers SYNTHdetect, an instrument designed for screening of colorless to near-colorless diamonds of all cuts mounted in jewelry. Loose stones can also be screened with no lower size ...

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 ...

Both vibrational Raman and FTIR spectroscopy have been widely applied in identifying synthetic and natural beryl (Wood and Nassau, 1968; Schmetzer and Kiefert, 1990; Huong et al., 2010). These methods ...

Figure 1. This emerald contains a brown crystal of the rare mineral parisite. There is also an oil-filled cavity showing a blue and orange flash effect, along with two large trapped gas bubbles. This ...

The Ponderosa mine is now producing commercial quantities of the gem-quality labradorite feldspar known as sunstone. This gem material exhibits unique optical and physical properties that include a ...

Diamond color is usually the result of selective absorption of incident white light. The unabsorbed portion of this light is transmitted through the diamond and is interpreted by the human vision ...

Yogo Gulch, discovered more than 100 years ago, is one of four major sapphire-producing areas in Montana, United States. Yogo sapphires are known for their uniform, well-saturated blue color; relative ...

For centuries, the Mogok Stone Tract of Burma has provided the world with its finest rubies. The mining district is situated about 700 km north of the capital city of Rangoon, with the rubies found ...

Gem-quality synthetic or laboratory-grown diamonds are more available in today’s jewelry marketplace than ever before, causing both interest and concern about lab-grown diamonds and whether ...

Most consumers in today’s marketplace choose round brilliant-cut diamonds fashioned to meet modern concepts of beauty. These sparkling gems represent the collective talents of generations of skilled ...