The bigger the diamond, the more it costs and has a higher cost per carat as well.

As mentioned earlier, diamonds are measure by their weight and Carat (abbreviated ct.) is the standard unit of weight measurement. One carat refers to 0.200 grams or approximately 0.007 ounces. To give you a relative point of reference, a very small plastic paper clip weighs about a carat.

When talking of diamond size, we generally use the word points. A one-carat is a 100 points; so a 50 point stone will be half a carat and 75 points refers to three quarters of a full carat weight. On the higher side, a 100 point is referred to as a carat and up to two decimal places for beyond full cartage like 1.09 is a carat and 9 points.

Magic Carat Weights

In the expensive world of diamonds, some carat weights give real value for money and are therefore known as Magic Carat Weights. It is most interesting to note that a full carat diamond will cost considerably more than a diamond that is 0.99 carat. Visually both pieces are same and the difference in size is miniscule but you can pay much less for 0.99 that for 1.00.

The same holds true for some other weights like:

• Half carat 0.50 ct.
• Three-quarter carat 0.75 ct.
• Carat 1.00 ct.
• One and a half carats 1.50 ct.
• Two carats 2.00 ct.

Carat Weight and Value

Another aspect to keep in mind is that carat weight does not work like weight of gold. Where 50 grams of gold costs half of 100 grams, diamonds have different quoted rates for each type or caratage of stone. A carat of loose stones of 25 points each go by a different per carat rate than a carat of loose stones of say 40 points each of similar clarity, cut and color.

As an example, we have here a comparative chart denoting value of round brilliant cut diamonds of the same quality (VS1 Clarity, F color, Ideal proportions) at different carat weights:

Carat Weight	0.50ct.	1.00ct.	1.50ct.	2.00ct.	3.00ct
Price Per Carat	$4,400	$7,800	$10,000	$12,500	$15,300
Estimated Value of Diamond	$2,200	$7,800	$15,000	$25,000	$45,900

The reason that values increase so dramatically with greater carat weight rests on the fact that there are fewer larger diamonds than small ones available, and rarity adds to the price. In brief, a larger single diamond costs more per carat than diamonds of smaller size though weighing the same all together.