Researchers have since plied the 45-carat diamond with every noninvasive tool in their arsenal, seeking to understand the precise distribution of boron atoms that lend the Hope its steely blue tint and why the diamond will glow, or phosphoresce, a spectral shade of blood orange when exposed to ultraviolet light.
|
|
Erwin's official Medal of Honor citation reads: > He was the radio operator of a B-29 airplane leading a group formation to > attack Koriyama, Japan. He was charged with the additional duty of dropping > phosphoresce smoke bombs to aid in assembling the group when the launching > point was reached. Upon entering the assembly area, aircraft fire and enemy > fighter opposition was encountered. Among the phosphoresce bombs launched by > S/Sgt.
|
|
Diamonds exhibit fluorescence, that is, they emit light of various colors and intensities under long-wave ultraviolet light (365 nm): Cape series stones (type Ia) usually fluoresce blue, and these stones may also phosphoresce yellow, a unique property among gemstones. Other possible long-wave fluorescence colors are green (usually in brown stones), yellow, mauve, or red (in type IIb diamonds). In natural diamonds, there is typically little if any response to short-wave ultraviolet, but the reverse is true of synthetic diamonds. Some natural type IIb diamonds phosphoresce blue after exposure to short-wave ultraviolet.
|
|
Erwin, 1 proved faulty, exploding in the launching chute, and shot > back into the interior of the aircraft, striking him in the face. The > burning phosphoresce obliterated his nose and completely blinded him. Smoke > filled the plane, obscuring the vision of the pilot. S/Sgt. Erwin realized > that the aircraft and crew would be lost if the burning bomb remained in the > plane.
|
|
Transitions between these three states are formally forbidden from occurring due to the requirement of spin flipping and or electron pairing. This means that atomic carbon phosphoresces in the near-infrared region of the electromagnetic spectrum at 981.1 nm. It can also fluoresce in infrared and phosphoresce in the blue region at 873.0 nm and 461.9 nm, respectively, upon excitation by ultraviolet radiation.
|
|
Very few boron atoms are required for this to happen—a typical ratio is one boron atom per 1,000,000 carbon atoms. Boron- doped diamonds transmit light down to ~250 nm and absorb some red and infrared light (hence the blue color); they may phosphoresce blue after exposure to shortwave ultraviolet light. Apart from optical absorption, boron acceptors have been detected by electron paramagnetic resonance.
|
|
Under low magnification, this birefringence is usually detectable as a visual doubling of a cut gemstone's rear facets or internal flaws. An effective diamond simulant should therefore be isotropic. Under longwave (365 nm) ultraviolet light, diamond may fluoresce a blue, yellow, green, mauve, or red of varying intensity. The most common fluorescence is blue, and such stones may also phosphoresce yellow—this is thought to be a unique combination among gemstones.
|
|