Black Diamonds v/s Diamonds

  • Diamond is an allotrope of carbon like graphite. The carbon atoms in a diamond are arranged in a variation of the face-centered cubic crystal structure. Black Diamonds are polycrystalline diamonds found in alluvial deposits. These diamonds are made up of many tiny diamond crystals and are therefore porous.
  • Diamonds due to their extraordinary optical characteristic have very few impurities or inclusions. They are clear, colorless and mostly transparent. Black Diamonds have heavy inclusions mainly graphite that is blackish in color thus making them opaque.

Black Diamonds v/s Diamonds

  • Diamonds have high optical dispersion that is the ability to disperse light in different colors which in turn grants them the brilliance and sparkle. Black diamonds being porous and opaque do not disperse any light, rather the black inclusions absorb the light, and thus they do not sparkle like white diamonds.
  • Diamonds are the hardest materials existing, but this hardness also makes them very brittle. A harsh blow can cause the diamond to break. Black diamonds are fragile due to their porous composition and heavy inclusions. A harsh blow can cause the diamond to break or chip.
  • Diamonds are valued for their transparency that is clarity, color, size and cut for the brilliance. Brilliant cut in round diamonds is know to grant maximum brilliance to the diamond. Diamonds are usually cut in limited styles to maintain the brilliance. Black Diamonds are also valued for the color, clarity, size and cut. Black diamonds can be cut in any desired shape without bothering about the brilliance.
  • Diamonds are one of the most expensive gems, due to their rarity. They make a great investment as their value has witnessed a constant acceleration. Black diamonds are cheaper than white diamonds but their value has grown many folds over the last five years.
  • Diamond has look alikes like Cubic Zirconia, synthetic diamonds, crystals, silicon carbides or similar stones like White topaz and more expensive white sapphire. Onyx, Jet, Black crystals etc.
  • Diamonds are treated to improve the white diamond’s color grade color and clarity, including laser drilling to remove inclusions, application of sealants to fill cracks. Black diamonds are mostly treated to enhance the dark gray color to black, they may be irradiated or heat treated.

BLACK DIAMONDS ARE CARBONADOS?

Yes, Black Diamonds are Carbonados – Carbonados have all the properties of the real diamonds but are dark grey- greenish black in color and are porous. The color of the Carbonados resembles charcoal, in fact the name ‘Carbonados’ means “burnt” in Portuguese. They were first discovered in Brazil around the 1840’s, though are supposed to be more than 2.6 to 3.8 billion years old. Carbonados have greater hardness than diamonds therefore were primarily used as abrasives and for cutting glass etc.

BLACK DIAMONDS ARE CARBONADOS?

Origin – There is quiet a hullabaloo about how Carbonados came into being. The most common theory suggests that black diamond like regular white diamonds are also formed from carbon under high-pressure conditions in the bowels of the Earth. Shock metamorphism induced by meteoritic impact on the surface of the earth and radiations-induced by abrupt fission of uranium and thorium are a couple of other theories. Few others argue that Carbonados or Black diamonds have come from the outer space. They believe to have fallen as meteors on earth millions of years ago. Thus are found in alluvial, sedimentary deposits instead in the bowels of the earth and have unusual properties. Moreover the availability of Carabonados is limited to the alluvial deposits in the Central African Republic and in Brazil. To support this theory it has been lately discovered that the micro crystals in Carbonado have traces of nitrogen, hydrogen, and osbornite which are otherwise found only in meteors.

Unique Constitution – Carbonados or Blacks diamonds are very different from white diamonds- they are black and do not sparkle. Carbonados are polycrystalline, ploy means many and crystalline means crystals; which mean carbonados are made of multiple nano/micro crystals sticking together unlike a white diamond that is one single crystal. These micro-crystals have vacancies in them that make them porous. Moreover when the light falls on the diamond it gets absorbed or lost in these vacancies rather than being reflected back which is why they do not sparkle.

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The Color– Black diamonds apart from being porous have heavy inclusions mostly graphite, pyrite or hematite that render the diamond opaque. These inclusions play an important role in determining the color intensity of the black diamonds. The color is also the result of the numerous cleavages or fractures that have become black due to graphitization. The color of the natural Black Diamond may range from grayish black to charcoal or dull gray depending on the inclusions. These not so perfectly black diamonds are heated or irradiated to improve the color. Natural-color black diamonds typically opaque and have a high luster that gives the stones a metallic appearance. However black diamonds are rare especially the naturally occurring black colored diamonds are very rare and are therefore very expensive.