Figure 1. Left: 18K yellow gold “Flames” ring with 25.19 ct Mexican fire opal. Right: This 18K yellow gold “Spice” ring ...

The authors examine the gemological properties and commercial potential of a new source of amber, discovered in 2020 on the Vietnamese island of Phu Quoc. It is the only known amber locality in ...

Many unusually large South Sea cultured pearls have been identified at GIA laboratories in the past (e.g., Fall 2013 Lab Notes, pp. 172–173; Summer 2023 Lab Notes, pp. 216–217). However, a recent ...

Examination of a 0.50 ct H-color type Ia natural diamond with SI 2 clarity recently revealed intriguing inclusions. Under the microscope, one crystal inclusion seen with a mirror reflection resembled ...

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Designed for clients who seek in-depth insights into every aspect of a jewelry item. Comprehensive analysis of the diamonds in an item, including number of stones, shape, estimated carat weight, color ...

Recently, the authors examined a 0.36 ct diamond with D color and SI 2 clarity. The diamond contained a cluster of cloud inclusions arranged to form an interesting pattern (see above). Best observed ...

A 1.09 ct D-color diamond grown by chemical vapor deposition (CVD) was recently submitted to the Mumbai laboratory. This submission displayed an interesting blue band, seen through the pavilion facets ...

Two specimens of faceted crystalized carbon - both are crystal clear and give off a kaleidoscope of spectral colors in direct light. They appear to be identical. One, however, is a billion or more ...

Diamonds are the most amazing of gems. Just as amazing, however, is how natural diamonds reach Earth’s surface. Diamonds are formed 150 to 700 km deep in Earth, and are then carried upward in a rare ...

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 ...

Aquamarine and heliodor are colored by Fe ions, an important coloring agent for beryl. Blue to yellow gem beryl was studied by quantitative spectroscopy and trace-element analytical techniques to ...