The situation has changed somewhat recently, with new production from Sri Lanka, Brazil, and Tanzania (Jarrett, 2015). However, demand for the gemstone has stayed high in the U.S., especially for large stones with high clarity and intense and distinctive color change (again, see figures 1–3 and 6).

market has been low since the 1990s, as the supplies from the initial rush in Brazil presumably started drying up (Costanza, 1998). In Sri Lanka (Zwaan, 1982 Zoysa, 1987, 2014), it is mined as a byproduct of corundum, cat’s-eye and nonphenomenal chrysoberyl, and other minerals. It has been mined in Russia (Kozlov, 2005 Schmetzer, 2010), Tanzania (Gübelin, 1976 Schmetzer and Malsy, 2011b) and Zimbabwe (Brown and Kelly, 1984 Schmetzer et al., 2011) as a byproduct of emerald mining, and in Brazil (Proctor, 1988 Cassedanne and Roditi, 1993 Voynick, 1988) and India (Newlay and Pashine, 1993 Patnaik and Nayak, 1993 Panjikar and Ramchandran,1997 Voynick, 1988 Valentini, 1998) along with cat’s-eye and nonphenomenal chrysoberyl, as well as other pegmatitic minerals. Overall production statistics are hard to evaluate. Photos by Robert Weldon/GIA courtesy of Omi Privé.Īlexandrite, particularly fine-quality material, is also very scarce it has generally been a byproduct of mining other major colored stones. Pinpoint light was used to reveal the stones’ chatoyancy. The image on the left was photographed with daylight-equivalent lighting and the image on the right with incandescent light. The design also features alexandrite and diamond melee accents. This matched pair of cat’s-eye alexandrites from Brazil exhibits double phenomena (color change and chatoyancy) and weighs a total of 2.43 carats. Because of its rare and attractive color-change phenomenon, alexandrite has been highly sought after and is one of the most valuable gemstones in the trade.įigure 3. Alexandrite is routinely described as “emerald by day, ruby by night.” It is a stone of duality-green or red, cool or warm, day or night (Levine, 2008). This phenomenal color change is caused by the presence of trace Cr 3+ substituting for Al 3+ in the chrysoberyl crystal structure. The most coveted alexandrites exhibit a lush green to greenish blue color in daylight and a warm, bright red shade in candlelight (Levine, 2008) some fine Brazilian and Indian alexandrite examples are shown in figures 1–3 and 6. 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. Comprehensive CAD/CAM For Jewelry Certificateįigure 1.

Alexandrite birth stone