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One of the greatest concerns with emerald filling is the degree of clarity enhancement such treatment represents. Stones that appear to have excellent clarity with the unaided eye are often revealed ...

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

Although the Art Deco period extends roughly from 1910 to well into the 1930s, it was primarily a product of the "Roaring '20s." This was a wonderfully decadent era. It was an age of Prohibition and ...

Figure 1. The GIA 7 Pearl Value Factors system classifies pearls according to size, shape, color, luster, surface, nacre, and matching. Composite photo by GIA staff. Prized by many cultures throughout ...

Fancy color diamonds are among the rarest and most valuable gemstones. Diamonds in the normal color range are colorless through light yellow and are described using the industry’s D-to-Z color-grading ...

Aquamarine, Maxixe-type (irradiated) beryl, and two types of hydrothermally grown synthetic blue beryl currently available in the marketplace were investigated by classical gemological methods, ...

A set of six antique brooches, set with diamonds and light blue cabochons, was investigated with microscopy, Raman analysis, and EDXRF spectroscopy. Most of the cabochons proved to be fossilized ...

Just over a century ago, in the summer of 1912, a workman’s pickaxe struck through the floor of an old tenement house in Cheapside, a commercial district near the renowned St. Paul’s Cathedral in ...

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 ...

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 ...

Gem-quality diaspore occupies an important position in the gem market due to its rarity, striking pleochroism, and color-change phenomenon (figure 1). The material’s value depends on these factors. A ...