A necklace made from oval gold links joined by diamond-set clasps and signed Cartier Paris excited bidders, who sent it climbing to $42,750, more than triple the estimate.
source : nytimes.com
For almost 100 years, cutters have been perfecting their art in effort to achieve the grandeur and luster of the round diamond.
A uniquely modified square Emerald. Being a trademark design cut, Asscher diamonds are short in supply and highly sought-after.
Brilliant, square diamonds with no trimmed corners. An extremely popular choice for engagement rings.
Rare and unique, the Radiant Diamond features beautiful barely trimmed corners. This blazing cut makes an exceptional choice.
Gently rounded like a cushion, this exceptional cut has been in high demand for over a century as a solitaire.
Pear
Pear shaped diamonds go back to the 1400s. These stones are most popular as engagement rings & pendants.
This slim and point-ended cut, set parallel to the finger & often embellished by accent stones. Popular for wedding rings.
The heart shape is mostly in demand in recent years for pendants. High color level is important as it is visible at the corners.
Elegant and luminous, oval diamonds compliment feminine fingers, and are usually extremely fashionable among small-handed women.
A rectangular cut of the emerald diamonds featuring trimmed corners and rectangular facets, popular when set with accent stones.
Also "Trilliant Diamonds", these stones are often used in stud earrings. Chosen wisely, this cut can be a splendid center stone.
The room was dimly lit. Armed guards stood at both entrances and enormous ironclad doors were slid shut to seal the gallery.
Nobody spoke above a whisper as we waited for the first glimpse in half a century of one of the world's most extraordinary gems.
The Wittelsbach-Graff Diamond was last seen in public at the 1958 World Exhibition in Brussels. After that, it disappeared and its whereabouts remained a mystery until Laurence Graff, a billionaire diamond dealer, bought it at auction in 2008, appending his surname.
He and his son Francois were in the gallery of the Smithsonian's National Museum of Natural History in Washington DC as the blue stone, was brought up from a secret vault and finally revealed.
Flawless beauty
"I've been privileged over the years to own some of the world's most important and famous diamonds, but I would say that the Wittelsbach-Graff is the most valuable and the most beautiful," he said.
Sitting unadorned on a silken white cloth, it glittered grey and blue in the low light. Classed as "internally flawless" it is said to have exceptional colour and becomes intense orange when viewed under ultraviolet light.
Diamond | |
---|---|
A scattering of round-brilliant cut diamonds shows off the many reflecting facets. | |
General | |
Category | Native Minerals |
Chemical formula | C |
Identification | |
Molecular Weight | 12.01 u |
Color | Typically yellow, brown or gray to colorless. Less often in blue, green, black, translucent white, pink, violet, orange, purple and red. |
Crystal habit | Octahedral |
Crystal system | Isometric-Hexoctahedral (Cubic) |
Cleavage | 111 (perfect in four directions) |
Fracture | Conchoidal - step like |
Mohs Scale hardness | 10[1] |
Luster | Adamantine |
Polish luster | Adamantine |
Refractive index | 2.4175–2.4178 |
Optical Properties | Singly Refractive |
Birefringence | none |
Dispersion | .044 |
Pleochroism | none |
Ultraviolet fluorescence | colorless to yellowish stones - inert to strong in long wave, and typically blue. Weaker in short wave. |
Absorption spectra | In pale yellow stones a 415.5 nm line is typical. Irradiated and annealed diamonds often show a line around 594 nm when cooled to low temperatures. |
Streak | White |
Specific gravity | 3.52 (+/- .01) |
Density | 3.5-3.53 |
Diaphaneity | Transparent to subtransparent to translucent |
Diamonds are specifically renowned as a material with superlative physical qualities; they make excellent abrasives because they can be scratched only by other diamonds, Borazon, ultrahard fullerite, or aggregated diamond nanorods, which also means they hold a polish extremely well and retain their lustre. Approximately 130 million carats (26,000 kg) are mined annually, with a total value of nearly USD $9 billion, and about 100,000 kg are synthesized annually.[2]
The name diamond derives from the ancient Greek adamas (αδάμας; “invincible”). They have been treasured as gemstones since their use as religious icons in ancient India and usage in engraving tools also dates to early human history.[3][4] Popularity of diamonds has risen since the 19th century because of increased supply, improved cutting and polishing techniques, growth in the world economy, and innovative and successful advertising campaigns. They are commonly judged by the “four Cs”: carat, clarity, color, and cut.
Roughly 49% of diamonds originate from central and southern Africa, although significant sources of the mineral have been discovered in Canada, India, Russia, Brazil, and Australia. They are mined from kimberlite and lamproite volcanic pipes, which brought to the surface the diamond crystals from deep in the Earth where the high pressure and temperature enables the formation of the crystals. The mining and distribution of natural diamonds are subjects of frequent controversy such as with concerns over the sale of conflict diamonds (aka blood diamonds) by African paramilitary groups.