The Kazanjian Red Diamond, one of only three red diamonds of more than five carats, is on display at the American Museum of Natural History. Credit: AMNH/D. Finnin.
From Live Science:
NEW YORK — Among colored diamonds, red is particularly rare, and mysterious, since no one knows for certain the origin of the color within the stone.
One of the three known red diamonds weighing more than 5 carats (1 gram), an emerald-cut stone about the size of a small fingertip rests against a gray background in an American Museum of Natural History display case. This stone, known as the Kazanjian Red Diamond, has a dark hue resembling that of a garnet or a ruby, and in its nearly century-long history, it has been mistaken for the latter.
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