Diamond is a solid form of carbon with a diamond cubic crystal structure. Diamond is renowned for its superlative physical qualities, most of which originate from the strong covalent bonding between its atoms. In particular, it has the highest hardness and thermal conductivity of any bulk material.
Considering their rarity, value, and of course their beauty, throughout history, many different time periods and cultures have created unique myths and legends about diamonds.
In the middle of 21st century the diamond grading standards were established.These standards are recognised worldwide- 4 C of diamond quality: Color, Clarity , Cut and Carat.
4Cs Color, Clarity, Cut and Carat.
One carat equals 200 milligrams in weight. For diamonds under one carat, each carat is divided into 100 points. 0.75 ct.= 75 points, 1/ 2 ct. = 50 points.
Color is one of the factors influencing the value of a diamond. The Color Scale extends from D ( colorless) to Z (light yellow or brown).
Although many people think of gem quality diamonds as colorless, truly colorless diamonds are actually very rare. Most diamonds used in jewelry are nearly colorless with tints of yellow and brown.
Color grades are determined by comparing each diamond to a master set. Each letter grade represents a range of color and is a measure of how noticeable a color is.
The Clarity Scale includes eleven clarity grades ranging from Flawless to I3.
Because diamonds form under tremendous heat and pressure, it is extremely rare to find a diamond that lacks any internal and external characteristics. These characteristics are a by-product of its formation and help gemologists separate natural diamonds from synthetics and simulants, and identify individual stones.
The Cut Scale ranges from Excellent to Poor.
A polished diamond’s beauty lies in its complex relationship with light. The magnificent display you see is made up of three attributes: Brightness is the combination of all white light reflecting from the surface and interior of a diamond. Fire describes the “flares” of color emitted from a diamond. Scintillation describes the pattern of light and dark areas and the sparkle you see when the diamond, the light, or the observer moves.