Top 20 Diamond Scams

The 20 most common scams in stores
and 13 precautions to avoid them.



What are the Four C’s?

The basic descriptors of diamond quality all begin with a “C”. Your first big step in finding the right diamond is to decide on the basic 4 C’s.The Four C’s of Diamond Quality are ::

  • Cut
  • Color
  • Clarity
  • Carat Weight


… is the single most important factor in the beauty of a diamond. It refers to two separate descriptors of the diamond’s appearance ::

  1. the shape
  2. quality of the craftsmanship

There are many popular shapes, from Round to Radiant, Princess, Cushion, Radiant, and many others.Cut quality used to be the most complicated subject in buying a diamond, but recent developments make it easier, namely the establishment and wide acceptance of Cut Grades by GIA and AGS, as well as other gemological institutions.

The two main independent labs, GTL (created by GIA), and AGSL (created by AGS), both established Cut Grades for Round Brilliants in about 2000, and this has helped simplify the most complicated part of diamond quality and value assessment. Grades are assigned by the labs after physical observation, laser measurements, and computer modeling. Light performance is computed and calculated to assess the overall beauty of the craftsmanship.


… is the relative color of a diamond. Generally the scale ranges from Colorless, to Near Colorless, to Faint Yellow, to Very Light Yellow, to Light Yellow. Color Grades are given a letter value by the GIA system, ranging from D for perfectly colorless, to Z for some yellow tint. Other Fancy Colors, such as blue, orange, red, green, and more intense yellows and browns, have their own color grading nomenclature. For the tutorials on my site, I will only be discussing the basic D-Z color grading system.


… is the relative purity of the structure of a diamond. Inclusions and Blemishes can range from easily visible to the untrained eye, to invisible to the eye but visible under 10x magnification, to non-existent under under 10x or 14x magnification with a microscope by a trained expert. The Clarity Grade is assessed and given on a Cert / Certificate and used in assessing the beauty and value of a diamond.

Carat Weight

… is the actual weight of a diamond, measured on a very sensitive digital scale at a laboratory, usually to the 1/1000th of a carat.The report will show the weight to the 1/100th of a carat, and sometimes to the 1/1000th.

Note :: When you use the word “size” for a diamond, it can be a little misleading, because the same weight can appear as different dimensions, when they are cut more deep or shallow. Use the term “weight” and you are safer in your discussions.