During the depths of the Depression, a middle-aged man with little more than ambition and charisma revolutionized the gem and jewelry industry. Robert M. Shipley established the Gemological Institute ...

In April 2014, a team from GIA visited major emerald and tourmaline sources in Brazil. One of the most exciting mines the team visited was the Cruzeiro tourmaline mine in the state of Minas Gerais, ...

The Blue Moon diamond has a cushion modified brilliant cut, weighs 12.03 ct, and measures 15.57 × 13.47 × 7.55 mm. Its small culet facet enabled us to perform spectroscopy through the parallel faces ...

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Field reports, videos, photography, and firsthand accounts from mines and industry hot spots around the world.

Ruby is the July birthstone – and it’s one of the most coveted of gems. The name is derived from the Latin word ruber, meaning “red” – the color of love and passion. Few things catch the eye like the ...

When people hear the word diamond, colorless diamonds generally come to mind—not the more exotic colors discussed earlier in this article series. In purchasing a diamond, they are likely to choose one ...

Of all the sapphire deposits found in Montana, the richest is in the Rock Creek (Gem Mountain) district. Between 1890 and the 1930s, over 65 tonnes of rough sapphire were recovered from this area and ...

There’s an old saying that whatever you are doing at the start of the year will reflect on the rest of the year. Hopefully this is true, because for the authors, 2014 truly started out right. The ...

Part 2 of 5 in the series: Value Factors, Design, and Cut Quality of Colored Gemstones (Non-Diamond). This article establishes a common language for discussing cutting styles, with a focus on basic ...

Figure 1. A comparison of the Mohs hardness scale and the Knoop hardness scale, a micro-hardness test where a pyramidal diamond point is pressed into the polished surface of the sample with a known ...

Natural-color pink diamonds are exceptional treasures. The lead article in this issue, based on GIA’s database of more than 90,000 diamonds in the pink, orangy pink, purple, red, and brown color ...