The market value of jadeite has risen dramatically in recent decades, often rivaling that of fine ruby and sapphire. Understanding the color origin of jadeite and reliably determining treatments have ...

North America has a long history of natural pearling owing in part to its very diverse and rich freshwater mussel resources. After the Civil War pearl jewelry gained greater popularity in the United ...

Diamonds have a long history as a premier gemstone—a natural consequence of their beauty, rarity, and superlative physical properties such as extreme hardness. Diamonds that are mined for use as ...

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.

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 ...

Raman spectroscopy confirmed the identity of the material as pezzottaite by an intense peak at ~1100 cm –1, which is not present in beryl. Fourier-transform infrared spectroscopy showed features ...

Figure 1. Glass in a silver brooch, hallmark from 1866. Private collection, photo by Jaroslav Hyršl. Tectites are members of a large group of impact glasses, formed by the collision of a meteorite on ...

Vietnam is a land of great diversity and beauty. From the hustle and bustle of Ho Chi Minh City to the beauty of Hạ Long Bay and Hoi An (both UNESCO World Heritage Sites), there are innumerable places ...

Once upon a time, gem cutting was a strict craft bound by centuries of tradition. The job of a lapidary was to cut a gemstone to ideal proportions while preserving as many carats as possible. Then ...

Gem inclusions are mineral crystals or cavities filled with fluid and/or gas that occur in a host gemstone. Many gems contain microscopic inclusions (ranging in size from >1 mm down to submicroscopic ...

This chart focuses primarily on the types of natural inclusions found in tourmaline, as well as the minerals in which tourmaline can be found as an inclusion. Treatments such as enhancement of ...

This raspberry-and mint-colored tourmaline—nicknamed the “Steamboat”—is one of the world’s finest and most valuable mineral specimens. Photo by Duncan Pay ...