blue diamond

Natural blue diamonds are very rare and belong to Ⅱ B type. Natural blue diamonds contain no nitrogen, but little boron. Boron atoms produce an acceptor band in diamond crystals. The acceptor band can absorb near-infrared radiation and long-wave visible light, thus making the diamond appear blue. The energy difference between the acceptor band and the valence band is very small, and the valence band electrons can jump to the acceptor band under the action of heat, making the diamond conductive, so the blue diamond is a semiconductor.

The GR 1 color center produced by radiation will also make colorless and nitrogen-free IIA diamonds produce blue with low saturation. This GR 1 color blue diamond contains no boron, and its infrared absorption spectrum has no absorption peak of typical blue diamond.

Fig. 3-6 A bright blue diamond in the Arctic Brilliant Diamond Series (provided by Tino Hammid/Aurora Gem Collection).

Figure 3-6 shows a bright blue diamond of 1. 19 carats in the Arctic Brilliant Diamond Series. Blue diamonds are rare, and there are even fewer blue diamonds with high saturation. Blue diamonds with such high saturation can be described as treasures. There are several blue diamonds in the collection of Arctic brilliant diamonds with high saturation, reaching a brilliant level.

When synthesizing diamonds, adding appropriate amount of boron can produce blue. In the process of synthesizing diamonds, nitrogen molecules in the air will remain mainly when filling raw materials, so the synthesized blue diamonds are often green. The green tone of artificial blue diamond is caused by the absorption of short-wave visible light by discrete nitrogen.

The most legendary and tragic of all diamonds is the blue "Hope" diamond (Figure 3-7). "Hope" diamond was produced in India, and was brought back to France by French travel explorer Tavernier in 1668 and presented to Louis XIV. The irregular "Tavinine" blue diamond with the original weight of1/kloc-0.5 carat was re-cut into a heart shape of 76. 13 carat by the Royal French driller. Shortly thereafter, the French royal family was unlucky again and again. During the French Revolution, this blue diamond was stolen from the palace and sent to England to be cut into the present 45.52-carat classical cushion. 1830, the blue diamond was bought by the dealer Hope for about 18000, and was named "Hope" from then on. After Hope went bankrupt due to gambling, "Hope" diamonds were also forced to sell at 190 1. Later, through the jeweler Cartier, the "Hope" diamond was transferred to American newspaper tycoon McLean. Unfortunately, McLean got this diamond of hope one after another. Two years after Mrs McLean's death, Winston bought the diamond of hope for 1949. 1958 Winston sent the Diamond of Hope to the Smithsonian Museum by ordinary mail. This "hope" blue diamond with a "spell" has been quietly displayed in the Winston Exhibition Hall of the Smithsonian Museum for people to watch. Although some people blame this blue hope diamond for all natural and man-made disasters in the United States after 1958, more people regard it as a masterpiece of nature and appreciate its unparalleled color and charm.

June 8, 2007 65438+20071October 8, 2007, a 6.04-carat blue diamond was sold at Sotheby's in Hong Kong for 7.98 million dollars, setting a new record of 65438 dollars +0.32 million dollars/carat. This 6.04-carat blue diamond is bright blue with flawless clarity. According to reports, this blue diamond may come from Prem ier M ine in South Africa.

Figure 3-7 Hope Diamond

(Ada Photography/Collection of Smithsonian Museum)

Brilliant blue, weighing 45.52 carats, is the most famous blue diamond in the world and the most tragic diamond.

Figure 3-8 A blue synthetic diamond collected by the author.

(Ada Photography/Ada Collection)

Its color is caused by doping boron.

Figure 3-9 Blue diamonds and their original stones (provided by Robert Weldon/Aurora Gemstone Collection)