Diamond Size: How much does
carat weight influence the price of a diamond?
The first factor
of the 4 Cs that most people learn is carat weight, which is
the best indication of a diamond's size. Let's take a minute
to cover carat weights in detail to understand how it effects
Diamond weights are measured in "carats." One carat
equals 1/142nd of an ounce, or 1/5th of a gram. In other words... there
are 142 carats in 1 ounce and 5 carats in 1 gram.
The word "carat"
comes from the ancient practice in India (where diamonds were
first discovered and traded) of measuring diamond weights with
the one thing in nature that is both small and the most consistent
in weight -- the carob seed. Thus the name "carat"
evolved in the English language, which is still equivalent to
approximately the weight of one carob bean.
You also may have
heard jewelers talking about "points" when discussing
diamond sizes. This does not refer to the number facets on a
diamond, but rather to its weight. Just like one pound is divided
into 16 ounces, one carat is divided into 100 points -- so each
point is 1/100th of a carat. A "10-point" diamond weighs
1/10th of a carat, and a 50-point stone weighs one-half carat.
Carat weight has
a great deal of influence on the price of a diamond -- more so
than one might imagine at first. Since larger stones are more
rare in nature, they are more expensive as well. For instance,
one diamond weighing 2 carats will always cost much more than
two diamonds of the same quality weighing 1 carat each.
Below is an approximate
comparison of the major diamond weights to act as a starting
point in your consideration.
Hold an actual
dime over the picture of one below. If the dime below is actual
size, then the diamond sizes in this chart are accurate for your
Knowing the 4 Cs is NOT enough to price a diamond accurately.
At least 13 factors
affect diamond value, including fluorescence, table percentage,
symmetry and other crucial details.
To find a price on any
diamond, use our Diamond Price Tutorial Page, which teaches you how to use online diamond databases to calculate what to pay for any
diamond. If you cannot find a good jeweler, we rate the top dealers for you.