How the Hearts are Formed
Below are views of Hearts & Arows being forming during the cutting process as they would be seen through a regular Hearts & Arrows Viewer. The leftmost photos show the diamond blocked in 8. The center pair shows the pavilion fully cut, with crown still in 8. The pair on the right show the fully formed Hearts & Arrows when pavilion and crown have both been finished.
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Thursday, August 2, 2007
Hearts & Arrows Formation and Grading
HEARTS & ARROWS
Russian Lab created Diamond is the BEST man-made diamond you can get! Each Hearts & Arrows stone is cut to the ideal proportions which must be met in order for a stone to display maximum sparkle and shine. The exact proportions of a Hearts and Arrows Ideal Cut stone are revealed when viewed through a star scope magnifier which shows an eight-point star pattern. This pattern is known as "hearts and arrows" in the diamond industry. Only stones cut to these perfect ideal proportions will reveal this pattern. And only with this cutting could a diamond be in its most brilliance!
These stones are formed under tremendous temperature (5000 degrees Fahrenheit) and possess optical characteristics almost the same as natural diamond. With a dispersive power greater than diamond (0.060 vs. 0.044), the overall effect is so similar it can even fool a trained gemologist.
Russian Lab diamonds are not cheap, they are retailing at US$200+ per carat and more for H&A Diamonds.
ABOUT LAB OR RUSSIAN DIAMONDS
Russia has an advantage these days, as fears mushroom about gem sales financing the wars in Sierra Leone, Angola and Congo "The Russians are an important source of non-bloodied stones," said John Meyer, an industry analyst with Societe Generale in London. "The diamond industry in Russia has had a pretty low profile ... and this could be a pretty good marketing tool for them."
More exports would bring increased government revenues - the state owns a majority stake of Alrosa - and good news for an economy still hung over from a decade of decline. Most Russian diamonds come from Sakha, formerly known as Yakutia, a province five times the size of Texas that straddles the Arctic Circle. Soviet authorities coaxed workers to the ever-frozen wilderness with bloated salaries and generous benefits. Alrosa has trimmed the work force, but production costs remain high - about five times as much as De Beers spends extracting stones from its South African deposits. Once they leave Yakutia, diamonds are guarded by a series of private militias. Addresses of the Moscow vaults are a prized secret.
Russia produces about 20 percent of the world's rough diamonds and has vast untapped reserves. Russia's diamond monopoly Alrosa would develop new mines and reach more markets.
"After 40 years in the diamond business, Russia has grown out of children's shorts and understands how to sell diamonds so as not to harm the market or our own interests," said Valery Rudakov, chief of Russia's precious gem reserves.
Classification of natural diamond
Type Ib diamond: Also contains nitrogen as an impurity but in dispersed substitutional form. Almost all synthetic diamonds are of this type.
Type IIa diamond: effectively free of nitrogen impurity. Very rare in nature, these diamonds have enhanced optical and thermal properties.
Type IIb diamond: A very pure type of diamond which has semiconducting properties: generally blue in colour. Extremely rare in nature.
Diamond Properties
Hardness
Low friction
Low adhesion to other materials
High thermal conductivity
Low thermal expansion coefficient
Wide (optical) transmission band
High refractive index
Chemical inertness
Bio-compatible
Radiation hardness
Electric insulator
Good electronic properties
Natural Diamond
WHAT IS DAIMOND ?
Density [g/cm3] : 3.52
Compressive strength [GPa] : 8.68
Fracture toughness [MPam1/2] : 3.40
Knoop hardness [GPa] : 57 - 104
Young's modulus [GPa] : 1141
Thermal expansion [10-6K-1] : 1.5 - 4.8
Thermal conductivity [Wm-1K-1] : 500 - 2000
Wear coefficient : 2.14 - 5.49