The Smithsonian Alexandrite was unearthed in Sri Lanka, and holds a cushion mixed cut. Typical of most alexandrite, the Smithsonian jewel is red and green in color, and weighs 65.08 carats. It is currently one of the rarest, and most valuable, jewels in the world.
Its status as the world’s largest alexandrite, however, is very much up for debate. In 2011, it was suggested that an alexandrite gemstone named the Naleem Alexandrite weighs over 112 carats, but this can’t be confirmed. It has also been written that a private owner in Japan has a 141.92 carat alexandrite that was certified by the State Gem Corporation. Very little information can be found about the gemstone, but it is listed as the largest cut alexandrite by the Guinness Book of Records website. At 141.92 carats, the alexandrite would be worth over $100 million.
However, until any of these can be confirmed, the Smithsonian remains the verified champion of alexandrite gemstones.