How To Buy A Diamond

This guide will explain how the 4C's, color, clarity, carat and cut, combine to give you the best value diamond, regardless of your budget.

Introduction
This guide is meant to assist you in finding the perfect diamond for you. There are several factors that combine to determine the overall cost of a diamond, and you should be aware of all of them in order to make an educated decision when comparing two or more diamonds or diamond rings. Understanding that diamonds are valued by their rarity, you can see that a colorless diamond with flawless clarity in a 5 carat size could easily fetch hundreds of thousands of dollars, because it is amazingly rare!

Color
The color scale ranges from D to Z. D is a pure white colorless diamond, while Z shows noticeable yellow.
D E F
G H I J
K L M
N - Z
COLORLESS
NEAR COLORLESS
NOTICEABLE YELLOW
WARM YELLOW
Diamonds in the JKL range and below are often set in yellow gold rather than white gold to mask the natural yellow color of the diamonds.
Color beyond the "Z" classification go into a range called "Fancy Yellow". Fancy Colored diamonds are natural and are caused by other elements being present during the process of carbon transforming into a diamond.
This is an example of a natural fancy yellow diamond set in a ring. http://www.overstock.com/cgi-bin/d2.cgi?page=proframe&prod_id=2176658&IID=prod2176658

Clarity
The Clarity of a diamond describes the level of inclusions or flaws, naturally contained inside the diamond. Flawless diamonds are extremely rare, flawed diamonds are quite common. Diamonds are naturally hard substances, the hardest of any natural stone. However, diamonds with severe inclusions (I2 and I3 grades) actually weaken the stone, and are more prone to breaking.
FL/IF
Flawless/Internally Flawless
VVS1/VVS2
Very Very Slightly Included
VS1/VS2
Very Slightly Included
SI1/SI2
Slightly Included
I1
Included 1
I2/I3
Very Included

Carat
Carat is a measure of the weight of the diamond. While a heavier diamond is often times also larger (as you can see on the chart below), it is not uncommon for two diamonds of the same carat weight to have slightly differing length and width.

Cut


Certificates
There are several companies in the world today issuing diamond certification. Of them, the Gemological Institute of America (GIA), the European Gemological Laboratory (EGL), and the International Gemological Institute (IGI) are considered to be the most reputable.
BEWARE many jewelry vendors may try to sell "unauthorized" or "home made" diamond certificates to convince consumers that their diamonds are of higher quality than they actually are. Honest websites such as Overstock.com will only call a diamond ring certified when it has been sent to one of the above independent gemological laboratories. Diamond certificates include descriptions of the diamond's color and clarity, as well as its measurements. A plot is also included to illustrate the location of any inclusions as well as the type of inclusions in the diamond.
Examples:
http://www.overstock.com/cgi-bin/d2.cgi?page=proframe&prod_id=1082725 http://www.overstock.com/cgi-bin/d2.cgi?page=proframe&prod_id=1736874 http://www.overstock.com/cgi-bin/d2.cgi?page=proframe&prod_id=488300 http://www.overstock.com/cgi-bin/d2.cgi?page=proframe&prod_id=2274832
Click below for GIA explanation of a diamond grading report

http://www.gia.edu/GIAReports/31515/anatomy_of_gia_reports.cfm#

Appraisals
Appraisals from companies like IGI are used for insurance purposes, as they establish a "replacement value" for each piece of jewelry. Many jewelry stores will appraise your jewelry for you. If your center diamond is certified, be sure to bring it with you to have your jewelry appraised.

http://omuse.overstock.com/wiki/How_To_Buy_A_Diamond