The 4 C's of diamonds are criteria jewelers use when grading diamonds,and they are the one you will need to understand to buy the right diamond for you.
First ,don't confuse diamond "cut " with "shape " Shape refers to the general outward appearance of the diamond, such as round, oval, emerald , heart . pear . etc.
The brilliance of a diamond depends heavily on its cut. When a diamond is well cut, its proper proportions will send all light entering the diamond out of the top of the stones. this is consideres an ideal cut and what you should be looking for .
The color used in this diagram is for presentation purposes Colorless diamonds are the most of desirable since they allow the most refraction of light [sparkle] . Off white diamond absorb light, inhibiting brilliance.
NOTE : Fancy color diamonds, which can be aby color from blue to green to bright yellow ; do not follow this rule as the are very rare and expensive . They are actually more valuable for their color.
All diamond have identifying charateristics , but most are invisible to the naked eye. To view a diamond,experts use a 10x magnifying loupe which allows them to see the appearance of tiny crystals, feathers or clouds. These natural phenomena are called inclusions. There are five categories in class that anyone interested in purchasing a diamond should be aware of when grading clarity.
Carat is often confused with size even though it is a measure of weight. The cut of a diamond can make it appear larger or amaller than its actual weight. The diagram below is for presentation and is not to scale.