The size of a diamond has the
biggest impact on its price. The metric carat, which equals 0.20 gram, is
the standard unit of weight for diamonds and most other gems. If other
factors are equal, the more a stone weighs, the more valuable it will be.
Here are several ways to
express 1 carat:
4 grainer (not
often used in retail environment)
It is very important not to mistake
carat weight as referring to the dimensions of a
diamond. It refers to weight only. Why the distinction?
Because weight can hide in different parts of the stone. You can have
a) well-cut, b) deep, or c) shallow Diamonds. Some may appear larger
than others due to its cut.
diamonds are expressed in the trade as a price per carat. So when we say
that the Carat Weight has the biggest impact on the price
of the stone, we refer to the unit price per
carat, not just the overall price of the whole
Diamond "A" = 0.25 carats and costs $1,000 per
carat. $1,000 x 0.25 = $250/stone.
Diamond "B" = 0.50 carats and
costs $1,250 per carat. $1,250 x 0.50 =
Some people may feel it is
more impressive to wear a 2 carat diamond than a 1 carat diamond.
But that's not necessarily true. A Ferrari may not be as big a car
as an Station wagon, but most would consider it more impressive.
How "big" is a
Many people would like to
"understand" carat sizes in real terms. Here's a simple trick to get an
idea. Simply take a ruler, and look at the table below. These are some
approximate, sample carat-weight to diameter-widths for popular
|0.25 ct. - 4.1
||0.50 ct. - 5.2
|0.75 ct. - 5.9
||1.00 ct. - 6.5
How much does "carat
weight" affect cost?
The effect of all the different
properties of Diamond on Cost is discussed in more detail in the Cost section. For carat weight, let's take a typical Diamond for an example,
and see what happens when we take it through different carat weights.
A Diamond of G color and SI1
Clarity will be in one Category of prices when it is between 0.50 - 0.69
carats. When you take that same quality Diamond and increase the size to
the next price category, which is the 0.70 - 0.89 carat range, the price
increase will be approximately $1,100 per carat. Increase
to the 0.90 - 0.99 carat range, and the price increase will be
approximately another $800 per carat. Increase to 1.00 -
1.49 carat range, and the increase will be approximately another $800
per carat. If you increase to the 1.50 - 1.99 carat
range, the price increase will be approximately $1,200 per