Hope Diamond
The Hope Diamond (previously “Le bleu de France”) is a large, 45.52 carats (9.10 g),deep-blue diamond, housed in the Smithsonian Natural History Museum in Washington, D.C. The Hope Diamond is blue to the naked eye because of trace amounts of boron within its crystal structure, but it exhibits red phosphorescence after exposure to ultraviolet light.It is classified as a Type IIb diamond, and is famous for supposedly being cursed. It is currently unset for the first time since it has been on display.
Physical properties
An examination in December 1988 by the Gemological Institute of America’s Gem Trade Lab (GIA-GTL) showed the diamond to weigh 45.52 carats (9.104 g) and described it as “fancy dark greyish-blue.” A re-examination in 1996 slightly rephrased that description as “fancy deep greyish-blue.” The stone exhibits an unusually intense and strongly-colored type of luminescence: after exposure to short-wave ultraviolet light, the diamond produces a brilliant red phosphorescence (’glow-in-the-dark’ effect) that persists for some time after the light source has been switched off. The clarity was determined to be VS1, with whitish graining present. The cut was described as being “cushion antique brilliant with a faceted girdle and extra facets on the pavilion.” The dimensions in terms of length, width, and depth are 25.60mm × 21.78mm × 12.00mm (1in × 7/8in × 15/32in).
Colour
In popular literature, many superlatives have been used to describe the Hope Diamond as a “superfine deep blue”, often comparing it to the color of a fine sapphire “blue of the most beautiful blue sapphire” (Deulafait). Other references include Mawe (1823), Ball (1835), Bruton (1978), Tolansky (1962). However, these descriptions are somewhat exaggerated.
As coloured diamond expert Stephen Hofer points out, blue diamonds similar to the Hope can be shown by colorimetric measurements to be grayer (lower in saturation) than blue sapphires. In 1996 The Gemological Institute of America’s Gem Trade Lab (GIA-GTL) examined the diamond and using their proprietary scale, graded it fancy deep grayish blue. Visually, the gray modifier (mask) is so dark (indigo) that it produces an “inky” effect appearing almost blackish-blue in incandescent light. Current photographs of the Hope Diamond utilize high-intensity light sources that tend to maximize the brilliance of gemstones.
According to specious later accounts, the original form of the Hope Diamond was stolen from an eye of a sculpted statue of the goddess Sita, the wife of Rama, the seventh avatar of Vishnu. However, much like the “curse of Tutankhamun”, this general type of “legend” was the invention of Western authors during the Victorian era,and the specific legends about the Hope Diamond’s “cursed origin” were invented in the early 20th century to add mystique to the stone and increase its sales appeal.