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

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 ...

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 ...

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 ...

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, ...

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 ...

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 ...

Figure 1. Sapphires from Madagascar: a beautiful 3.29 ct untreated faceted stone and an assortment of rough in the background. Madagascar has produced many high-quality stones in the last few years ...

Diamonds are known for their hardness – their ability to resist scratches and abrasions. But diamonds are not impervious to damage, since their hardness is uneven along different crystal directions.

In November 2022, a parcel of 24 approximately 0.5–1.2 ct spinel crystals, described as cobalt-diffused, were obtained directly from a treater by the research team at GIA in Bangkok. Of these, seven ...

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 ...

The Karowe Diamond Mine in Botswana, owned and operated by Lucara Diamond Corp., has gained international recognition for producing large, high-quality type IaB or coexistence of IaB with IIa diamonds ...