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Smithsonian National Museum of Natural History

Elbaite (var. cat's eye tourmaline)

No description of this
                                          asset is available
Photo by Ken Larsen. Click to zoom.
Catalog Number NMNH G11504-00
Locality Brazil
Weight 55.36 ct

Gift of David Yurman Enterprises LLC in 2015.

Elbaite is a colorful member of the tourmaline group of minerals. The name tourmaline comes from the Sinhalese word “turmali,” which applied to different gemstones found in Sri Lanka. Tourmaline gems cover the complete range of the color spectrum, but in exquisite shades unlike those of any other gem material. Although tourmaline is best known in shades of green and red or pink, it can also be blue, purple, yellow, brown, and colorless. This tourmaline from Minas Gerais, Brazil exhibits the optical phenomenon called chatoyancy. Chatoyancy is light reflected off of parallel inclusions of microscopic tubes or crystals of another mineral inside the gemstone. When a stone is cut with a domed top and flat bottom, called a cabochon, the reflected light is focused into a bright band that forms an “eye” across the top of the stone. The term “cat’s eye” refers to the resemblance of the phenomenon with the slits of cat’s pupils. This dark bluish-green cat’s eye tourmaline has a well-defined sharp eye and weighs 55.36ct.


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