This immediately created a royal and romantic aura around this variety of chrysoberyl. INTRODUCTIONĪfter the discovery of a gem mineral with unusual color-change behavior in the Russian Ural Mountains during the early 1830s, Swedish mineralogist Nils Adolf Erik Nordenskiöld named this new gem alexandrite in 1834 in honor of the future Czar Alexander II (Kozlov, 2005). Future work may help to differentiate alexandrites from other localities.
The data obtained so far allow us to accurately determine geographic origin for alexandrites from Russia, Brazil, Sri Lanka, Tanzania, and India. The reference materials studied here were examined thoroughly for their trace element chemistry profiles, characteristic color-change ranges under daylight-equivalent and incandescent illumination, and inclusion scenes. Alexandrite is often recovered as a byproduct of mining for other gemstones (e.g., emerald and corundum), so it can be difficult to secure reliable parcels of samples because production is typically erratic and unpredictable. Unfortunately, collecting reliable samples with known provenance can be very difficult. In 2016, GIA began researching geographic origin of alexandrite with the intent of offering origin determination as a laboratory service. Alexandrites from Russia and Brazil are usually more highly valued than those from other countries. The gem and jewelry trade has come to place increasing importance on the geographic origin of alexandrite, as it can have a significant impact on value. Photos by Robert Weldon/GIA courtesy of Omi Privé.
Detailed procedures for photographing the alexandrites shown in this article are provided in appendixes 2 and 3. The image on the left was photographed in daylight-equivalent lighting, the image on the right in incandescent light. The designs also feature melee-cut alexandrites of unknown provenance and diamonds. Bottom row, left to right: Rings featuring a 1.71 ct oval and a 0.72 ct cushion-cut alexandrite. Top row, left to right: A three-stone alexandrite ring with a 1.35 ct center oval flanked by two smaller ovals with a combined weight of 1.29 carats and a ring with a 1.32 ct kite-shaped center stone flanked by two kite-shaped diamonds weighing a total of 0.32 carats. A group of rings featuring alexandrite from Brazil.
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