Figure 1. The vivid colors seen in fine gem-quality spinel are derived from the mixing between multiple different chromophores in a range of ratios and concentrations, as in this fine 13.52 ct ...

Tanzanite is one of the most popular colored gemstones in the world.- Courtesy Tanzanite Foundation ™ Tanzanite is a versatile gemstone that comes in a variety of sizes and cutting styles. Although it ...

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 ...

Through extensive hands-on practice using gemstones, you will explore grading the color, clarity and cut quality of a wide range of colored stones. Coursework includes the study of the GIA Colored ...

The popular GIA Graduate Jeweler program blends a foundational technical education with the practical skills needed in the modern jewelry industry while encouraging students to express their ...

For over 100 years, reference has been made to a unique sapphire, the color of a lotus blossom, the padparadscha. Yet the precise hue represented by this rare stone has been a subject of discussion, ...

Gem-quality spessartine garnet and grossular garnet have been discovered in Altay, China. Gemological and mineralogical studies show that their properties are typical for these garnet species.

Vivid blue, green, and purple-to-violet cuprian elbaites, renowned in the gem trade as “Paraíba” tourmalines, continue to be recovered in small amounts from northeastern Brazil. Since the initial ...

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 ...

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 ...

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.

The sparks will fly − and your diamond will shine − when you follow these cleaning tips. Diamond is the hardest natural substance on Earth. It can cut any kind of rock or metal, but only another ...