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 ...

7.9-cm tall crystal. Both are from Sappat, Kohistan, Pakistan. - Jeffrey Scovil Gem miners find peridot as irregular nodules (rounded rocks with peridot crystals inside) in some lava flows in the ...

A listing of prominent auction houses specializing in gemstones and fine jewelry. The following list has been compiled for informational purposes only and does not imply endorsement by GIA. This is a ...

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 ...

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, ...

A baroque pearl forms the body of a Triton in this jewel. © Victoria and Albert Museum, London. People have coveted natural pearls as symbols of wealth and status ...

There are many jewelry trade associations located throughout the world. This list is not comprehensive. Many regional groups will be found under their main association like Jewelers of America or the ...

A 43-carat alexandrite in the collection of the British Museum. Abundant alexandrite deposits were first discovered in 1830 in Russia’s Ural Mountains. Those first alexandrites were of very fine ...

Search a city or postal code to find retailers who carry GIA-graded diamonds or have GIA-trained staff. Results will include addresses, store hours and directions. Store hours reflected on Retailer ...

The red and green dyes in this bracelet’s amber pieces can fade over time. Hardness and toughness Gem and mineral hardness is measured on the Mohs scale. The numbers are based on the relative ease or ...

As an international jewelry hub and world destination commercial center, Hong Kong is the quintessential location for the gem and jewelry sector. Combine that with educational powerhouse GIA, and you ...

Figure 1. Pleochroism in a 15 ct tanzanite, as seen with the unaided eye through the crown and the pavilion sides and ends. Photo by Wimon Manorotkul. In describing colored gemstones, the major ...