The international system of diamond classification and identification is known as the 4 C Diamond Grading System.
The 4 C's are namely:
Carat Clarity Colour Cut
I have designated a seperate page / pages to explain each of the circumstances that influence diamonds and precious stones. It would be hasty to say that any single one of the above C 's is the most important aspect when it comes to a stone's value.
Many people think that bigger is better, when it comes to evaluating precious stones size is not even one of the 4 C's. Even then a larger stone could easily be worth less than a smaller better quality stone. It is important to understand each of the 4 C's in order to determine a precious stone's true value and quality.
the '5th' C: