Diamond is a unique member of the jem world. Part of that uniqueness come from the fact that it's made of a single element and that is carbon.
In most minerals, regular repeating patterns of atoms form an internal arrangement called crystal structure. Mineralogist and geologist classify crystals by their geometric properties and the symmetry of their internal crystal structures.
The categories are called crystal systems. Diamond belong to the cubic system, well formed cubic crystals are evenly proportioned and balanced. Garnet, spinel, platinum, and gold are also cubic minerals.
Crystal structure affects diamond in ways that are especially important to cutters. In some directions the atoms in a diamond crystal are closer together than in others. This makes that direction harder and unsuitable for cutting and polishing. And on the other side in some directions there are fewer carbon atoms with more space between them than in others.
In gem quality category, the shape of a rough diamond crystal is the most important factor in its potential value as a gemstone. Tow crystals with the same color and clarity might be equal in weight, yet one can be worth more than the other just on the basis of shape alone.
As the story goes, a little girl was watching a sculptor chisel a block of marble. Slowly, a figure took shape before her eyes. Suddenly, the surprised girl asked, how did you know there was a lion in there? Thousand of years ago, people considered diamond rough too sacred to cut or shape. They believed that tampering with it would destroy its super natural powers. Only rulers were allowed to wear this mysterious gift of the earth - and only if they left its magic undisturbed.
Uncut diamond appeared in Europe in the fourth century BC, when Alexander the Great expeditions opened up limited trade between east and west. At that time India was the only known diamond producing.
Around the mid-1300s, European and Indian gem cutters began to cut and shape rough diamond, by that time, caravans were transporting rough from India to Venice, Italy - an established trade centre. Compared to modern brilliant cuts, ancient finished diamonds were very plain. Actual examples of these diamonds are rare.
Cut the shape of finished gem and the number and angles of its facets plays a big part in a diamonds value. A rough diamonds exterior hides the finished stone's potential power to reflect, bend and break up light. Its potential for fire and flash can only be reached by cutting and polishing facets onto its surface.
When cutters decide how to get the most value out of rough diamond, they consider not only its crystal structure, but also its outward shape. To retain the most weight cutters follow the shape of the rough as closely as possible.
The Point cut was the earliest diamond cut and it was popular into the 15th century. It closely followed the rough's octahedral shape. Cutters used a stationary polishing surface coated with diamond grit and olive oil to polish off bumps and growth marks from the sides.
In the mid to late 1400 cutters began fashioning existing point cuts into a new style: the table cut. To create a table cut, the cutter removed the top point of the octahedron' double pyramid by rubbing it on a board treated with diamond dust and olive oil. This resulted in a square polished facet that resembled the table top.
The rose cut appeared in the early sixteenth century and was popular until the nineteenth century. Unlike the table cut it was not designed for octahedral rough instead it provided an efficient way to produce the largest possible gem from flattened rough.
In the early 1700, while sifting through river gravel for gold in mines Gerais, Brazil, miners found some odd crystals among the pebbles. The miners used them to keep score during their card games until an official who was familiar with diamond rough realized what they had discovered.Read more>
More than 500 years of experimentation led to the introduction of the modern brilliant cut in the early 1900. its intricate proportions showcase a diamonds brilliance and fire with dazzling effectiveness.
The modern round brilliant has a round girdle outline, symmetrically placed triangular and kite shaped facets, a table that larger than 50 percent of the girdle diameter, and a small culet or none at all.
Soon variation on the modern round brilliant became popular world wide. Manufacturers even modified its facet arrangement to fit other shapes such as the marquise, pear, cushion and oval. It remains the dominant diamond cut in the market place today.
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