The superb clarity and color of the Chalk Emerald ranks it among the world's finest Colombian emeralds. This outstanding 37.8-carat emerald exhibits the velvety deep green color that is most highly prized. The finest emeralds are found in the region around Muzo and Chivor, Colombia. These green gems were used by indigenous peoples for at least 1,000 years before the arrival of the Spanish conquistadors in the 16th century. Although spurred primarily by their passion for gold and silver, the Spanish quickly recognized the potential of the exquisite green crystals and took control of the mines. Emeralds became popular among European royalty and were shipped from the New World by the boatload. The great richness of the Colombian mines led to a glut of emeralds in Europe, triggering a brisk trade of the gemstones to the Middle East and India. The Mogul rulers in India were especially fond of emeralds and encouraged a vast gem cutting and jewelry industry. Many finished pieces were traded back to Europe. According to legend, the Chalk Emerald was once the centerpiece of an emerald and diamond necklace belonging to a Maharani of the former state of Baroda, India. It originally weighed 38.4 carats, but was recut and set in a platinum and gold ring designed by Harry Winston, Inc., where it is surrounded by 60 pear-shaped diamonds totaling 15 carats. It was donated to the Smithsonian by Mr. and Mrs. O. Roy Chalk in 1972 and is on display in the Gem Gallery at the National Museum of Natural History.