Diamond Structure and Properties
Composition: Diamond is carbon (C) in essence.
Color Diamond's color can be white, yellow, pink, brown, black (carbonado), red, green, blue, or transparent.
Occurrences Magmatic rocks, kimberlitic pipes: Russia, South Africa, Australia. Historically, India, Brazil, Namibia, Angola, and Congo.
Gem quality stones are rare. More frequent are industry grade diamonds.
The largest diamond of gemstone quality is the famous Cullian diamond. Its weight was over 3100 carats, which means about 620 grams.
The largest known faceted diamond is the Golden Jubilee. It weighs 546 carats after faceting, and 755 carats before.
Other famous diamonds include the blue Hope diamond (44 carats), and the green Dresden (76 carats).
Diamonds are among the rarest gems. Because of their exceptional hardness they are also the most enduring.
The specimens with too many imperfections to be used in jewelry can still be used in other industries because of their hardness (for example the black, carbonado varieties). For example, they can be used in industrial applications as abrasives, for drilling or sanding.
Diamonds belong to a group of rare minerals, such as gold or copper, composed of only a single element. They are pure carbon.
They are created 95 to 150 km under the surface of the earth, under tremendous pressure and heat. Only one type of rock has the honor of accommodating them: kimberlite.
Kimberlite is formed in a narrow tubular volcanic channels, which can be found on every continent.
Washed from the eroded channels of kimberlite, diamonds can be found in the waterways and ocean shores, like many other gemstones.
How are They Formed?
Diamonds are formed deep within the upper mantle of the earth. This happens below the earth's crust, in narrow volcanic channels called kimberlite channels.
The intense heat and pressure from surrounding the elemental carbon leads to formation of diamonds.
Geologists believe that magma explosions through the kimbertite channels have a huge, devastating power. While speeding through the crust to the surface of the earth, this magma carries the diamonds along.
Can You Believe the Range?
Diamond - the hardest substance on Earth, and graphite in your pencil, one of the softest substances on earth, have exactly the same chemical composition - they are both made of pure carbon.
What changes is the crystal structure only.
In graphite, the atoms of carbon are arranged in two-dimensional layers that can easily slide over each other.
In diamond, the atoms of carbon are arranged in a hard, three-dimensional compact grid.
Can You Transform Graphite into Diamond?
Sure you can. If you want to convert a pen into a diamond, just apply pressure. It takes some 450,000 kg per square inch, and some heat to reach temperature around 1650 degrees Celsius.
Strange but True - Hope Diamond
Legend has it that once upon a time there was a blue diamond of exceptional value and beauty embedded in a form of a 112-carat eye on the statue of Hindu goddess Sita.
When the stone was stolen, the story goes, the goddess has predicted misfortune to anyone who would come into its possession. The French King Louis XIV wore it only once, and shortly after died of smallpox. Louis XVI and Marie Antoinette also wore it and ended up on the guillotine. Later owners have experienced similar bad luck.
The gem was named after one of its owners, Henry Thomas Hope. Today it is on display at the Smithsonian Institute in Washington DC, USA.